CN103136602A - Health risk prediction of trichloromethane of water supply network and evaluation method thereof - Google Patents

Abstract

Disclosed are health risk prediction of trichloromethane of a water supply network and an evaluation method of the health risk prediction of the trichloromethane of the water supply network. The evaluation method of the health risk prediction of the trichloromethane of the water supply network comprises steps as below: selecting three kinds of water nodes of a drinkable water supplying network, continuously sampling different nodes in a year, and measuring trichloromethane concentration, chlorine consumption amount, total organic carbon, water temperature, potential of hydrogen (PH) value, special ultraviolet absorbance (SUVA) value and ammonia concentration of water at each node; building a calculation risk model of the trichloromethane, carrying out principal component analysis of argument pointers, and carrying out logistic regression modeling; carrying out the health risk evaluation which comprises steps of determining an evaluation formula and a calculation method; calculating carcinogenic risks of water of a pipe network in different exposure ways; calculating danger index of the trichloromethane of different exposure ways and carrying out health risk evaluation of the water quality of the pipe network. The health risk prediction of the trichloromethane of the water supply network and the evaluation method of the health risk prediction of the trichloromethane of the water supply network provide a risk prediction method of the trichloromethane of the water of the pipe network, design risk levels of the trichloromethane, and provide a method and a reference of the management of the water quality of the pipe network.

Description

The health risk predicting and appraising method of methenyl choloride in water supply network

Technical field

The present invention relates to a kind of water quality prediction for water system and evaluation method.The health risk predicting and appraising method that particularly relates to methenyl choloride in a kind of water supply network.

Background technology

Drinking water disinfection is the necessary means of guaranteeing water quality safety, but the chlorine residue in output water can continue through the pipe network transmission ﹠ distribution time with water in organism reaction, thereby produce the DBPs (Disinfection by-products, DBPs) with carcinogenesis, threaten the safety of potable water ^[1]The World Health Organization's report, the DBPs of potable water are mainly the volatile matter with haloform (THMs) representative ^[2], methenyl choloride accounts for more than 75% of its total amount in haloform class DBPs ^[3-5]At present, international cancer research institution (IARC) has been classified as methenyl choloride B2 level carcinogen (namely the mankind being had potential carcinogenicity).Therefore, this paper chooses methenyl choloride and carries out research and analysis as the typical DBPs in pipe network water.

Along with the raising of society to safe water problem attention rate, the water quality health risk of estimating water supply network has become the major issue that the water supply network water quality management faces.So-called risk assessment is namely screening and identification harm in qualitative or quantitative analysis, and for the methenyl choloride index in water, the content of risk assessment has just comprised the analysis to its carcinogenic risk and hazard index.

For a long time, made more research at methenyl choloride aspect the impact of water quality safety abroad ^[6,7], domestic research in this one side starts to walk evening relatively, and the research index is also more single ^[8]It should be noted that domestic and international existing research ^[9-11]In, the data that methenyl choloride concentration value used obtains according to many report statistics often are not measured value, with the larger discrepancy of actual conditions existence of water quality under the research sight; Parameter in the health risk assessment model is directly applied mechanically Environmental Protection Agency's recommendation usually, lack to supply water in survey region, the investigation of water actual conditions, with actual conditions in survey region, larger difference is arranged ^[12]The health risk assessment of carrying out, often for the pipe network water user of single type, the methenyl choloride route of exposure of considering is often not comprehensive yet, thereby can't estimate rationally, exactly the health risk of pipe network water.

Summary of the invention

Technical matters to be solved by this invention is, provides a kind of and can predict comprehensively, estimate the method for the health risk of pipe network water under the methenyl choloride impact.

The technical solution adopted in the present invention is: a kind of health risk predicting and appraising method of methenyl choloride in water supply network comprised as the next stage:

1) choose three class water nodes in the potable water water supply network, to different node serial samplings, measured methenyl choloride concentration, chlorine consumption, total organic carbon, water temperature, pH value, SUVA value and ammonia nitrogen concentration in each Nodes water in 1 year;

2) set up the calculation risk model of methenyl choloride, comprise the independent variable index is carried out principal component analysis, and carry out the logistic regression modeling;

3) carry out health risk assessment, comprise the steps:

(1) determine judgement schematics and computing method

(2) according to the pipe network water body carcinogenic risk under the different route of exposure of step (1) calculating;

(3) according to the methenyl choloride hazard index under the different route of exposure of step (1) calculating;

(4) carry out the health risk assessment of ductwork water quality.

Stage 1) three category nodes described in are respectively residential node, office type node and communal facility type node.

Stage 1) in, the assay method of methenyl choloride is to adopt improved U.S. EPA 502.2 methods, namely uses the vapor-phase chromatography of liquid-liquid extraction method and having electronic acquisition detector.

Stage 2) the calculation risk model of setting up methenyl choloride described in is, at first, carry out principal component analysis with chlorine consumption, total organic carbon, water temperature, pH value, SUVA value and the ammonia nitrogen concentration that detects as the independent variable index, characterize original independent variable information with contribution rate of accumulative total greater than three major components of 0.7.Then, be concentration≤60 μ g/L according to the index request to methenyl choloride in drinking water sanitary standard, set the criterion of binary variable: when methenyl choloride concentration≤60 μ g/L, node methenyl choloride concentration safety, binary variable Alarm=0; When methenyl choloride concentration〉during 60 μ g/L, the methenyl choloride risk appears in node, binary variable Alarm=1.At last, use the logistic regression method to set up the logical relation of three major components and node methenyl choloride risk, obtain the calculation risk probability model of node methenyl choloride:

$P=\frac{\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}{1+\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}$

In formula, P is the calculation risk probable value of methenyl choloride, and Prin1, Prin2 and Prin3 are respectively contribution rate of accumulative total and reach numerical value greater than the major component more than 0.7, carry out i, f in SAS software ₁, f ₂And f ₃Recurrence calculate, the regression result that obtains model parameter is: i=4.5336, f ₁=-0.5665, f ₂=0.8971, f ₃=-0.3649.

After completing the model parameter recurrence, calculate the risk probability of respectively organizing the corresponding methenyl choloride of testing result of water quality independent variable index, and the CONCENTRATION DISTRIBUTION situation of methenyl choloride under each risk probability is made statistics.

Stage 3) judgement schematics described in is:

(a) the methenyl choloride carcinogenic risk=CDIoral take the diet absorption as route of exposure * PForal

$\mathrm{CDIoral}=\frac{\mathrm{CW}\&times;\mathrm{IR}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

In formula:

The potential carcinogen of PForal---specific carcinogen take the diet absorption as route of exposure characterizes the effect of carcinogenicity, with reference to the numerical value that Environmental Protection Agency and U.S.'s integrated risk infosystem provide, gets 6.1 * 10 ^-3(mg/kg/day) ^-1

CDIoral---diet is taken in the chronic average daily uptake of methenyl choloride of approach, mg/kg/day;

CW---the methenyl choloride concentration in water, mg/L;

IR---day absorption water yield, L/day, the day water uptake of residential, office type and communal facility type Nodes is taken as respectively 3.5 ± 0.21L/day, 2.5 ± 0.11L/day and 1.5 ± 0.06L/day;

ED---individual open-assembly time, days, the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days;

BW---whose body weight, individual average weight are 58.70kg;

AT---individual mean lifetime, days, the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, is 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years;

(b) the methenyl choloride carcinogenic risk=CDIderm take skin contact as route of exposure * PFderm

$\mathrm{CDIderm}=\frac{\mathrm{CW}\&times;\mathrm{SA}\&times;\mathrm{PC}\&times;\mathrm{ET}\&times;\mathrm{EF}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

In formula:

The potential carcinogen of PFderm---specific carcinogen take skin contact as route of exposure characterizes the effect of carcinogenicity, and the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 6.1 * 10 ^-3(mg/kg/day) ^-1

CDIderm---the chronic average daily uptake of methenyl choloride take skin contact as approach, mg/kg/day;

CW---the concentration of methenyl choloride in water, μ g/L;

SA---the skin surface that can contact is long-pending, m ², the male sex gets 1.697m ², the women gets 1.531m ², be 105.20:100 by M-F, calculating mean value is 1.616m ²

PC---the permeability of the specific chemical pollutant of skin surface, m/h, the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 0.0020m/h;

ET---open-assembly time, h/event refers to expose duration at every turn, is taken as 0.2h/event;

EF---expose frequency, event/day, wherein EPA recommendation 1event/day is adopted in the residential block, and this value is statistic, and the exposure frequency of office type node is taken as 0.3 ± 0.05event/day, and communal facility type node is taken as 1.25 ± 0.15event/day;

ED---individual open-assembly time, day, the residential Nodes is got the recommendation 365days/year of Environmental Protection Agency * 71.4year, and the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days;

BW---whose body weight, Chinese male average weight 62.7kg, women's average weight 54.4kg are 105.20:100 according to M-F, calculating individual average weight is 58.70kg;

AT---individual mean lifetime, days, the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, is 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years.

(c) the methenyl choloride carcinogenic risk=CDIinhalation take the steam suction as route of exposure * PFinhalation

$\mathrm{CDIinhalation}=\frac{\mathrm{CA}\&times;\mathrm{IR}\&times;\mathrm{ET}\&times;\mathrm{EF}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

$\mathrm{CA}=\frac{Q_W{P}_V\mathrm{CW}}{k_{a}V}(1-e^{-k_{a}t})\&times;{10}^{-3}$

In formula:

The potential carcinogen of PFinhalation---specific carcinogen take the steam suction as route of exposure characterizes the effect of carcinogenicity, and the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 6.6 * 10 ^-3(mg/kg/day) ^-1

CDIinhalation---the chronic average daily uptake of methenyl choloride take the steam suction as approach, mg/kg/day;

CA---the concentration of methenyl choloride in water vapor, mg/m ³

IR---suck speed, m ³/ h, the male sex are 19m ³/ d, women are 14m ³/ d is 105.20:100 by M-F, and calculating mean value is 16.56m ³/ d, i.e. 0.69m ³/ h;

ET---open-assembly time, h/event is taken as 0.2h/event;

EF---expose frequency, event/day, wherein, the residential node adopts EPA recommendation 1event/day, and the exposure frequency of office type and communal facility type Nodes is taken as respectively 0.3 ± 0.05event/day and 0.75 ± 0.10event/day;

ED---individual open-assembly time, day, the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days;

BW---whose body weight, Chinese male average weight 62.7kg, women's average weight 54.4kg, M-F is 105.20:100, calculating individual average weight is 58.70kg;

AT---individual mean lifetime, days, the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, is 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years.

Q _w---water velocity, get 10L/min; P _V---the conversion ratio of methenyl choloride from water to the air, get 8.76%; CW---the concentration of methenyl choloride in water, μ g/L; V---volume per capita during shower is got 2m ³k _a---air exchange rate during shower, get 0.021; T---the shower time, get 12min;

(d) the methenyl choloride hazard index under different route of exposure, computing formula is as follows:

Methenyl choloride hazard index=CDIoral/RfD take the diet absorption as route of exposure

Methenyl choloride hazard index=CDIderm/RfD take skin contact as route of exposure

In formula:

RfD---characterize the reference dose of the non-carcinogenic dangerous effect of predetermined substance, mg/kg/day, the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 1.0 * 10 ^-2Mg/kg/day;

CDIoral---diet is taken in the chronic average daily uptake of methenyl choloride of approach, mg/kg/day;

The chronic average daily uptake of the methenyl choloride of CDIderm---skin contact approach, mg/kg/day.

Stage 3) in, (1) described computing method are following steps:

(1) according to the water quality detection record of each node chlorine consumption, total organic carbon, water temperature, pH value, SUVA and ammonia nitrogen, the data value of simulating the water-quality guideline of described each node chlorine consumption, total organic carbon, water temperature, pH value, SUVA and ammonia nitrogen with monte carlo method;

(2) according to the stage 2) in the result of the principal component analysis (PCA) that obtains, adopt the Monte Carlo simulation result of chlorine consumption, total organic carbon, water temperature, pH value, SUVA and six model independent variable indexs of ammonia nitrogen, calculate the concrete numerical value of three major components, and in conjunction with the stage 2) in the formula that provides $P=\frac{\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}{1+\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}$ Completing the methenyl choloride risk probability calculates;

(3) take the middle gained methenyl choloride risk probability result of calculation of step (2) as the basis, according to the stage 2) in the methenyl choloride CONCENTRATION DISTRIBUTION corresponding to the different risk probabilities of calculation risk model of methenyl choloride, with monte carlo method simulate in step (2) the corresponding methenyl choloride concentration of risk probability numerical value;

(4) with the methenyl choloride concentration numerical value of step (3) gained, bring the stage 3 into) in methenyl choloride carcinogenic risk, hazard index formula under given each route of exposure, thereby complete calculating.

Stage 3) the pipe network water body carcinogenic risk under the different approaches described in comprises: the cancer risk take the diet absorption as route of exposure, the cancer risk take skin contact as route of exposure and the cancer risk take the steam suction as route of exposure.

The methenyl choloride hazard index of the different approaches the stage 3) includes: diet is taken in the methenyl choloride hazard index of approach and the methenyl choloride hazard index of skin contact approach.

Stage 3) health risk assessment of carrying out ductwork water quality described in is, pipe network water carcinogenic risk under the different route of exposure that calculate and methenyl choloride hazard index are the basis, by with the human health risk assessment guide rule of Environmental Protection Agency issue in material carcinogenic risk grade and the risk index assessment criterion stipulated compare, estimate the health risk situation of pipe network water.

The health risk predicting and appraising method of methenyl choloride in water supply network of the present invention has following beneficial effect:

(1) provide the methenyl choloride Risk Forecast Method of pipe network water, designed the methenyl choloride risk class, for the ductwork water quality management provides method;

(2) simulated the various situations of ductwork water quality with monte carlo method, the evaluation of carrying out has based on this reflected the health risk situation of pipe network water all sidedly;

(3) multipath methenyl choloride carcinogenic risk and the hazard index of dissimilar water Nodes have been analyzed, pointed out all types of health risk characteristics with the water spot place, compared the difference of dissimilar node health risk situation, for the ductwork water quality management provides reference.

Description of drawings

Fig. 1 is the methenyl choloride CONCENTRATION DISTRIBUTION under different risk probabilities;

Fig. 2 a is the probability distribution that the polymorphic type take the diet absorption as route of exposure is used water spot cancer risk;

Fig. 2 b is the probability distribution that the polymorphic type take skin contact as route of exposure is used water spot cancer risk;

Fig. 2 c is the probability distribution that the polymorphic type take the steam suction as route of exposure is used water spot cancer risk;

Fig. 3 a is the cumulative probability figure that the polymorphic type take the diet absorption as route of exposure is used water spot methenyl choloride hazard index;

Fig. 3 b is the cumulative probability figure that the polymorphic type take skin contact as route of exposure is used water spot methenyl choloride hazard index.

Embodiment

Make a detailed description below in conjunction with embodiment and the accompanying drawing health risk predicting and appraising method to methenyl choloride in water supply network of the present invention.

The health risk predicting and appraising method of methenyl choloride in water supply network of the present invention comprised as the next stage:

1) choose three class water nodes in the potable water water supply network, to different node serial samplings, measured methenyl choloride concentration, chlorine consumption, total organic carbon, water temperature, pH value, SUVA value (absorbance of water sample under the 254nm ultraviolet wavelength and the ratio of water sample total organic carbon) and ammonia nitrogen concentration in each Nodes water in 1 year;

Wherein, described three category nodes are respectively residential node, office type node and communal facility type node.The assay method of described methenyl choloride is to adopt improved U.S. EPA 502.2 methods, namely uses the vapor-phase chromatography of liquid-liquid extraction method and having electronic acquisition detector ^[13], the detection method of other indexs is seen document [14].

2) set up the calculation risk model of methenyl choloride, comprise the independent variable index is carried out principal component analysis, and carry out the logistic regression modeling;

The described calculation risk model of setting up methenyl choloride is, at first, with the chlorine consumption, total organic carbon, water temperature, pH value, SUVA value and the ammonia nitrogen concentration that detect as the independent variable index ^[15,16]Carry out principal component analysis, characterize original independent variable information with contribution rate of accumulative total greater than three major components of 0.7.Then, be concentration≤60 μ g/L according to the index request to methenyl choloride in drinking water sanitary standard GB5749-2006, set the criterion of binary variable: when methenyl choloride concentration≤60 μ g/L, node methenyl choloride concentration safety, binary variable Alarm=0; When methenyl choloride concentration〉during 60 μ g/L, the methenyl choloride risk appears in node, binary variable Alarm=1.At last, use the logistic regression method to set up the logical relation of three major components and node methenyl choloride risk, obtain the calculation risk probability model of node methenyl choloride ^[17,18]:

$P=\frac{\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}{1+\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}---\left(1\right)$

In formula, P is the calculation risk probable value of methenyl choloride, and Prin1, Prin2 and Prin3 are respectively contribution rate of accumulative total and reach numerical value greater than the major component more than 0.7, carry out i, f in SAS software ₁, f ₂And f ₃Recurrence calculate, the regression result that obtains model parameter is: i=4.5336, f ₁=-0.5665, f ₂=0.8971, f ₃=-0.3649.

After completing the model parameter recurrence, calculate the risk probability of respectively organizing the corresponding methenyl choloride of testing result of water quality independent variable index, and the CONCENTRATION DISTRIBUTION situation of methenyl choloride under each risk probability is made statistics.

Fig. 1 is the methenyl choloride CONCENTRATION DISTRIBUTION under different risk probabilities, and table 1 is the statistics that the CONCENTRATION DISTRIBUTION situation of methenyl choloride under each risk probability is made.

The statistics of methenyl choloride CONCENTRATION DISTRIBUTION under the different risk probabilities of table 1

A. formula

In be the μ expectation value, σ is standard deviation, min is minimum value, max is maximal value.

According to result shown in table 1, the calculation risk probability is 0.0～0.2 o'clock, and in pipe network water, the Cmax of methenyl choloride is no more than 60 μ g/L, and expectation value is 28.64 μ g/L, in pipe network water, methenyl choloride exceeds standard probability lower than 0.01, can think the methenyl choloride index safety of pipe network water body; The calculation risk probability is 0.2～0.6 o'clock, and the expectation that methenyl choloride detects sample is 55.25 μ g/L, and the concentration range in 50% core fiducial interval is 45～60 μ g/L, and the methenyl choloride probability that exceeds standard is 0.36, and pipe network water risk occurred on the methenyl choloride index; The calculation risk probability is 0.6～1.0 o'clock, the scope that the methenyl choloride Cmax of detection sample reaches 96.11 μ g/L, 50% core fiducial interval is 70～80 μ g/L, all in drinking water sanitary standard, the limit value of methenyl choloride being required (must not higher than 60 μ g/L), the risk of pipe network water on the methenyl choloride index is higher.

According to above-mentioned analysis, this patent is divided into Three Estate with the methenyl choloride risk of pipe network water: low equivalent risk (the calculation risk probability is 0.0～0.2), medium risk (risk probability is 0.2～0.6) and high equivalent risk (risk probability is 0.6～1.0).Observing Fig. 1 can find out, under above-mentioned three calculation risk grades, the core fiducial interval of methenyl choloride CONCENTRATION DISTRIBUTION does not have overlapping, and in, low-risk core fiducial interval all is distributed in below 60 μ g/L, apparently higher than 60 μ g/L, namely the division of risk class is scientific and reasonable for high risk core fiducial interval.When using said method future, can be according to chlorine consumption, total organic carbon, water temperature, pH value, SUVA and the ammonia nitrogen index of ductwork water quality on-line monitoring point collection, step 2 by embodiment) content described in, complete risk probability and calculate, and then judge the risk class of methenyl choloride index in water and the concrete concentration range of methenyl choloride in water is made certain estimation.

3) carry out health risk assessment, comprise the steps:

(1) determine judgement schematics and computing method

Described judgement schematics is:

(a) the methenyl choloride carcinogenic risk=CDIoral take the diet absorption as route of exposure * PForal

$\mathrm{CDIoral}=\frac{\mathrm{CW}\&times;\mathrm{IR}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

In formula:

The potential carcinogen of PForal---specific carcinogen take the diet absorption as route of exposure characterizes the effect of carcinogenicity, with reference to the numerical value that Environmental Protection Agency and U.S.'s integrated risk infosystem provide, gets 6.1 * 10 ^-3(mg/kg/day) ^-1

CDIoral---diet is taken in the chronic average daily uptake of methenyl choloride of approach, mg/kg/day;

CW---the methenyl choloride concentration in water, mg/L;

IR---day absorption water yield, L/day is according to relevant regulations and document ^[25]Finding, a day water uptake is 1.0～4.4L/day per capita under normal operation, in conjunction with the water characteristics of dissimilar node, the day water uptake of residential, office type and communal facility type Nodes is taken as respectively 3.5 ± 0.21L/day, 2.5 ± 0.11L/day and 1.5 ± 0.06L/day;

ED---individual open-assembly time, days, open-assembly time refers to that individuality is exposed to total duration of a certain pollutant, in this patent, the residential Nodes is got the recommendation 365days/year of Environmental Protection Agency * 71.4year, consider that in this patent, the pipe network as goal in research is in high school district, due to cold, the existence in summer vacation can make the individual open-assembly time of dissimilar Nodes different, by the statistics calendar of imparting knowledge to students, the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days,

BW---whose body weight, according to the achievement in research in document [25], Chinese male average weight 62.7kg, women's average weight 54.4kg are 105.20:100 according to the 6th census M-F of China, calculating individual average weight is 58.70kg;

AT---individual mean lifetime, days, according to the achievement in research in document [25], the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, be 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years;

(b) the methenyl choloride carcinogenic risk=CDIderm take skin contact as route of exposure * PFderm

$\mathrm{CDIderm}=\frac{\mathrm{CW}\&times;\mathrm{SA}\&times;\mathrm{PC}\&times;\mathrm{ET}\&times;\mathrm{EF}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

In formula:

The potential carcinogen of PFderm---specific carcinogen take skin contact as route of exposure characterizes the effect of carcinogenicity, and the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 6.1 * 10 ^-3(mg/kg/day) ^-1

CDIderm---the chronic average daily uptake of methenyl choloride take skin contact as approach, mg/kg/day;

CW---the concentration of methenyl choloride in water, μ g/L;

SA---the skin surface that can contact is long-pending, m ², according to the result of study of document [25], the male sex gets 1.697m ², the women gets 1.531m ², be 105.20:100 by M-F, calculating mean value is 1.616m ²

PC---the permeability of the specific chemical pollutant of skin surface, m/h, the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 0.0020m/h;

ET---open-assembly time, h/event refers to expose duration, according to list of references at every turn ^[21,22]Be taken as 0.2h/event;

EF---expose frequency, event/day refers to expose the frequency (few time more than a day) of generation.Wherein EPA recommendation 1event/day is adopted in the residential block, this value is statistic, this patent considers that shower and swimming are main methenyl choloride skin contact approach, the exposure frequency of reference residential block, the exposure frequency of office type node is taken as 0.3 ± 0.05event/day, and communal facility type node is taken as 1.25 ± 0.15event/day;

ED---individual open-assembly time, day, open-assembly time refers to that individuality is exposed to total duration of a certain pollutant, in this patent, the residential Nodes is got the recommendation 365days/year of Environmental Protection Agency * 71.4year, consider that in this patent, the pipe network as goal in research is in high school district, due to cold, the existence in summer vacation can make the individual open-assembly time of dissimilar Nodes different, by the statistics calendar of imparting knowledge to students, the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days,

BW---whose body weight, according to the achievement in research in document [25], Chinese male average weight 62.7kg, women's average weight 54.4kg are 105.20:100 according to the 6th census M-F of China, calculating individual average weight is 58.70kg;

AT---individual mean lifetime, days, according to the achievement in research in document [25], the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, be 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years.

(c) the methenyl choloride carcinogenic risk=CDIinhalation take the steam suction as route of exposure * PFinhalation

$\mathrm{CDIinhalation}=\frac{\mathrm{CA}\&times;\mathrm{IR}\&times;\mathrm{ET}\&times;\mathrm{EF}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

$\mathrm{CA}=\frac{Q_W{P}_V\mathrm{CW}}{k_{a}V}(1-e^{-k_{a}t})\&times;{10}^{-3}$

In formula:

The potential carcinogen of PFinhalation---specific carcinogen take the steam suction as route of exposure characterizes the effect of carcinogenicity, and the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 6.6 * 10 ^-3(mg/kg/day) ^-1

CDIinhalation---the chronic average daily uptake of methenyl choloride take the steam suction as approach, mg/kg/day;

CA---the concentration of methenyl choloride in water vapor, mg/m ³

IR---suck speed, m ³/ h is according to document ^[25]In achievement in research, the male sex is 19m ³/ d, women are 14m ³/ d is 105.20:100 by M-F, and calculating mean value is 16.56m ³/ d, i.e. 0.69m ³/ h;

ET---open-assembly time, h/event refers to expose duration at every turn, suck by steam when this patent is considered shower to be the most important inhalation route of methenyl choloride, so open-assembly time be taken as the time of each shower, and according to list of references ^[22-24]Achievement in research be taken as 0.2h/event;

EF---expose frequency, event/day refers to expose the frequency (few time more than a day) of generation.Wherein, the residential node adopts EPA recommendation 1event/day, this patent is considered when mainly occurring in shower with vapor form suction methenyl choloride, therefore the exposure frequency of reference residential node, the exposure frequency of office type and communal facility type Nodes is taken as respectively 0.3 ± 0.05event/day and 0.75 ± 0.10event/day;

ED---individual open-assembly time, day, open-assembly time refers to that individuality is exposed to total duration of a certain pollutant, in this patent, the residential Nodes is got the recommendation 365days/year of Environmental Protection Agency * 71.4year, consider that in this patent, the pipe network as goal in research is in high school district, due to cold, the existence in summer vacation can make the individual open-assembly time of dissimilar Nodes different, by the statistics calendar of imparting knowledge to students, the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days,

BW---whose body weight, according to the achievement in research in document [25], Chinese male average weight 62.7kg, women's average weight 54.4kg are 105.20:100 according to the 6th census M-F of China, calculating individual average weight is 58.70kg;

AT---individual mean lifetime, days, according to the achievement in research in document [25], the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, be 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years.

Q _w---water velocity, get 10L/min; P _V---the conversion ratio of methenyl choloride from water to the air, get 8.76%; CW---the concentration of methenyl choloride in water, μ g/L; V---volume per capita during shower is got 2m ³k _a---air exchange rate during shower, get 0.021; T---the shower time, get 12min; Wherein, Q _w, P _V, V, k _aWith t all according to list of references ^[22]Choose.

(d) the methenyl choloride hazard index under different route of exposure, computing formula is as follows:

Methenyl choloride hazard index=CDIoral/RfD take the diet absorption as route of exposure

Methenyl choloride hazard index=CDIderm/RfD take skin contact as route of exposure

In formula:

RfD---characterize the reference dose of the non-carcinogenic dangerous effect of predetermined substance, mg/kg/day, the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 1.0 * 10 ^-2Mg/kg/day;

CDIoral---diet is taken in the chronic average daily uptake of methenyl choloride of approach, mg/kg/day;

The chronic average daily uptake of the methenyl choloride of CDIderm---skin contact approach, mg/kg/day.

Due to the restriction of physical condition, often very limited by the data that monitoring water quality on line point on pipe network collects, the water quality situation that is not monitored to if health risk assessment just based on above-mentioned limited image data, will be ignored some physical presence.Be the health risk of thoroughly evaluating pipe network water, this patent has been used Monte Carlo method [19,20] the various water quality situations of pipe network water of having come comprehensive simulated, and completes on this basis the water body health risk assessment.Described computing method are following steps:

(a) according to the water quality detection record of each node chlorine consumption, total organic carbon, water temperature, pH value, SUVA and ammonia nitrogen, the data value of simulating the water-quality guideline of described each node chlorine consumption, total organic carbon, water temperature, pH value, SUVA and ammonia nitrogen with monte carlo method;

(b) according to the stage 2) result of the principal component analysis (PCA) that obtains of middle age, adopt the Monte Carlo simulation result of chlorine consumption, total organic carbon, water temperature, pH value, SUVA and six model independent variable indexs of ammonia nitrogen, calculate the concrete numerical value of three major components, and in conjunction with the stage 2) in the formula (1) that provides: $P=\frac{\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}{1+\mathrm{EXP}(-i-{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\&times;\mathrm{Prin}1-{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="HDA00002932325600021.png,HDA00002932325600022.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\&times;\mathrm{Prin}2-{\mathrm{<figure-callout\; id="3"\; label="f"\; filenames="HDA00002932325600022.png,HDA00002932325600031.png"\; state="\{\{state\}\}">f</figure-callout>}}_3\&times;\mathrm{Prin}3)}$ Completing the methenyl choloride risk probability calculates;

(c) take the middle gained methenyl choloride risk probability result of calculation of step (b) as the basis, according to the stage 2) described in methenyl choloride CONCENTRATION DISTRIBUTION corresponding to different risk probabilities, with monte carlo method simulate in step (b) the corresponding methenyl choloride concentration of risk probability numerical value;

(d) with the methenyl choloride concentration numerical value of step (c) gained, bring the stage 3 into) in methenyl choloride carcinogenic risk, hazard index formula under given each route of exposure, thereby complete calculating.

(2) according to the pipe network water body carcinogenic risk under the different route of exposure of step (1) calculating;

Pipe network water body carcinogenic risk under described different approaches comprises: the cancer risk take the diet absorption as route of exposure, the cancer risk take skin contact as route of exposure and the cancer risk take the steam suction as route of exposure.

(3) according to the methenyl choloride hazard index under the different route of exposure of step (1) calculating;

The methenyl choloride hazard index of described different approaches includes: diet is taken in the methenyl choloride hazard index of approach and the methenyl choloride hazard index of skin contact approach.

(4) carry out the health risk assessment of ductwork water quality

The described health risk assessment of carrying out ductwork water quality is, pipe network water carcinogenic risk under the different route of exposure that calculate and methenyl choloride hazard index are the basis, by with the human health risk assessment guide rule of Environmental Protection Agency issue in material carcinogenic risk grade and the risk index assessment criterion stipulated compare, estimate the health risk situation of pipe network water.The described health risk assessment of carrying out ductwork water quality is specially:

Fig. 2 a-c is under different route of exposure, the probability distribution graph of the pipe network water carcinogenic risk of all types of Nodes.According to the human health risk assessment guide rule of Environmental Protection Agency's issue, the carcinogenic risk of material has been divided into level Four: carcinogenic risk＜10 ^-6, 10 ^-6＜carcinogenic risk＜10 ^-5, 10 ^-5＜carcinogenic risk＜10 ^-4And carcinogenic risk＞10 ^-4According to the guide rule content, the carcinogenic risk of grade one (carcinogenic risk＜10 ^-6) be " insignificant " risk, need not take action to reduce risk level; The carcinogenic risk of grade two and grade three (is respectively 10 ^-6＜carcinogenic risk＜10 ^-5With 10 ^-5＜carcinogenic risk＜10 ^-4) be " usually acceptable " risk, needn't preferentially take action to reduce risk level; Grade four (carcinogenic risk＞10 ^-4) be " unacceptable " risk, must take action to reduce risk level.

Observe Fig. 2 a-2c as can be known, the residential Nodes drops in the 3rd risk class (10 except the cancer risk of taking in approach by diet has 50% probability ^-5＜carcinogenic risk＜10 ^-4), the cancer risk under all the other two approach all is positioned under first, second risk class and (is respectively carcinogenic risk＜10 ^-6With 10 ^-6＜carcinogenic risk＜10 ^-5).Obviously, the methenyl choloride cancer risk of residential Nodes pipe network water is all the risk of " insignificant " or " usually acceptable ", and water quality safety is better.

Office type Nodes, the cancer risk of taking in by diet approximately have 20% probability to fall in the 3rd risk class (10 ^-5＜carcinogenic risk＜10 ^-4), have the probability near 80% to fall into below the second risk class, the cancer risk under all the other two approach almost completely is in the first risk class.Obviously, the methenyl choloride cancer risk of office type Nodes pipe network water is all the risk of " insignificant " or " usually acceptable ", and the water quality health risk is lower than the residential node.

Communal facility type Nodes, the cancer risk under many route of exposure is almost all lower than 10 ^-5(namely almost completely falling into the second risk class following), the methenyl choloride cancer risk under each route of exposure is all the risk of " insignificant " or " usually acceptable ", and the water quality health risk is lower than the residential node.

According to above-mentioned analysis, the pipe network water methenyl choloride cancer risk of residential node is obviously higher than other two category nodes, this be due to the crowd in the life-time of residential Nodes and water frequency often higher than the situation under other two category nodes.Therefore, residential merits attention more with the pipe network water carcinogenic risk at water spot place.As the public place, the pipe network water carcinogenic risk of office type and communal facility type Nodes is less, means that the cancer risk level that the crowd is exposed in the activities such as work, production, motion is lower.

Fig. 3 a-3b is under multipath, the polymorphic type cumulative probability figure of water spot methenyl choloride hazard index.According to the human health risk assessment guide rule of Environmental Protection Agency issue, if the hazard index of a certain material lower than 1.0, can be thought this material " without remarkable risk ".

Observing Fig. 3 a-3b can find out, the residential Nodes, hazard index cumulative probability curve under diet absorption and skin contact approach occurs raising fast at 0.15～0.25 and 0.02～0.045 respectively, and namely the hazard index under above-mentioned two approach concentrates on respectively 0.15～0.25 and 0.02～0.045; Hazard index cumulative probability curve under two route of exposure increases to 1.0 0.40 and 0.08 when following respectively, namely the pipe network water methenyl choloride hazard index under each route of exposure of residential Nodes all be starkly lower than 1.0, to healthy " without remarkable risk ".

Office type Nodes, hazard index cumulative probability curve under diet absorption and skin contact approach occurs raising fast at 0.10～0.20 and 0.007～0.015 respectively, and namely the hazard index under above-mentioned two approach concentrates on respectively 0.10～0.20 and 0.007～0.015; Hazard index cumulative probability curve under each route of exposure increases to 1.0 0.40 and 0.03 when following respectively, and obviously, the pipe network water methenyl choloride hazard index under each route of exposure of office type Nodes all is starkly lower than 1.0, to healthy " without remarkable risk ".With respect to the residential node, the water quality methenyl choloride hazard index of office type Nodes is lower.

Communal facility type Nodes, hazard index cumulative probability curve under diet absorption and skin contact approach occurs raising fast at 0.07～0.13 and 0.03～0.07 respectively, and namely the hazard index under above-mentioned two approach concentrates on respectively 0.07～0.13 and 0.03～0.07; Hazard index cumulative probability curve under each route of exposure increases to 1.0 0.25 and 0.14 when following respectively, and obviously, the pipe network water methenyl choloride hazard index under each route of exposure of communal facility type Nodes all is starkly lower than 1.0, to healthy " without remarkable risk ".With respect to residential node and office type node, under the diet approach of communal facility type Nodes the methenyl choloride hazard index obviously under lower, skin contact approach the methenyl choloride hazard index higher, this water use model difference from the three different water nodes of class has obvious relation.

All types of Nodes pipe network water carcinogenic risks and hazard index analysis result under comprehensive above-mentioned different route of exposure, can draw: in the current research zone, the carcinogenic risk of pipe network water is all risk, the pipe network water " without remarkable risk " aspect the methenyl choloride hazard index of " insignificant " or " usually acceptable ", and the health risk of ductwork water quality is lower.

List of references used in the present invention is as follows:

[1] Han Chang, Liu Shaogang, enemy wild goose tail feather, etc. disinfection by-product of drinking water analysis and Developments [J]. environmental protection science .2009 (1): 12-16.

[2]Who.Disinfectant?and?disinfectant?by-product[Z].2000.

[3] Wang Jinyu, Chen Linghu, Zhao Chen, etc. the Primary Study of Influence Factor of Trihalomethanes Formation in Drinking Water [J]. water purification technology .2009 (6): 30-34.

[4]Sun?Y,Wu?Q,Hu?H,et?al.Effect?of?bromide?on?the?formation?of?disinfection?by-products?during?wastewater?chlorination[J].Water?Research.2009,43(9):2391-2398.

[5] Tian Yimei, Liu Huina, Wang Yang. the forecasting research of methenyl choloride [J] in the distribution system of water supply. hydrotechny .2007 (1): 35-38.

[6]Hamidin?N,Yu?Q?J,Connell?D?W.Human?health?risk?assessment?of?chlorinated?disinfection?by-products?in?drinking?water?using?a?probabilistic?approach[J].Water?Research.2008,42(13):3263-3274.

[7]Chowdhury?S,Hall?K.RETRACTED:Human?health?risk?assessment?from?exposure?to?trihalomethanes?in?Canadian?cities[J].Environment?International.2010,36(5):453-460.

[8] You Hanhu, Xiao Bing, Zhang Yanping, etc. Foshan district potable water haloform health risk assessment [J]. contemporary medical science .2011 (23): 156-158.

[9]Chowdhury?S,Hall?K.RETRACTED:?Human?health?risk?assessment?from?exposure?to?trihalomethanes?in?Canadian?cities[J].Environment?International.2010,36(5):453-460.

[10] Hu Yuqian. the health risk assessment of haloform research [D] in the potable water of Hangzhou. Zhejiang University, 2005.

[11] Zhao Yanling, Zhang Guibin, Zhang Meiyun, etc. the carcinogenic risk evaluation [J] of haloform to the adult in the tap water of Chaoyang District, Beijing City. environment and health magazine .2012 (5): 437-439.

[12] Zhao Yanling, Zhang Guibin, Zhang Meiyun, etc. the carcinogenic risk evaluation [J] of haloform to the adult in the tap water of Chaoyang District, Beijing City. environment and health magazine .2012 (5): 437-439.

[13] Wu Yan. the research [D] of DBPs in distribution system of water supply system. Harbin Institute of Technology, 2006.

[14] Wei Fusheng of State Environmental Protection Administration chief editor, water and effluent monitoring analytical approach editorial committee. water and effluent monitoring analytical approach [M]. Beijing: China Environmental Science Press, 2002:784.

[15]Sun?Y,Wu?Q,Hu?H,et?al.Effect?of?ammonia?on?the?formation?of?THMs?and?HAAs?in?secondary?effluent?chlorination[J].Chemosphere.2009,76(5):631-637.

[16]Sun?Y,Wu?Q,Hu?H,et?al.Effects?of?operating?conditions?on?THMs?and?HAAs?formation?during?wastewater?chlorination[J].Journal?of?Hazardous?Materials.?2009,?168(2–3):?1290-1295.

[17] Hong Nan, Hou Jun .SAS for Windows statistical analysis system study course [M]. Beijing: Electronic Industry Press, 2001:444.

[18] Li Dongfeng. study course SAS system of statistical software and S language [M]. Beijing: People's Telecon Publishing House, 2006:275.

[19]Chowdhury?S,Champagne?P,Mclellan?P?J.Uncertainty?characterization?approaches?for?risk?assessment?of?DBPs?in?drinking?water:A?review[J].Journal?of?Environmental?Management.2009,90(5):1680-1691.

[20] Hu Yuqian. the health risk assessment of haloform research [D] in the potable water of Hangzhou. Zhejiang University, 2005.

[21]Wang?W,Ye?B,Yang?L,et?al.Risk?assessment?on?disinfection?by-products?of?drinking?water?of?different?water?sources?and?disinfection?processes[J].Environment?International.2007,33(2):219-225.

[22]Chowdhury?S,Hall?K.RETRACTED:Human?health?risk?assessment?from?exposure?to?trihalomethanes?in?Canadian?cities[J].Environment?International.2010,36(5):453-460.

[23]Uyak?V.Multi-pathway?risk?assessment?of?trihalomethanes?exposure?in?Istanbul?drinking?water?supplies[J].Environment?International.2006,32(1):12-21.

[24]Epa.Risk?Assessment?Guidance?for?Superfund?Volume:Human?Health?Evaluation?Manual(Part?A)Interim?Final[Z].1989:?EPA/540/1-89/002.

[25] Wang Zongshuan, Duan Xiaoli, Liu Ping, etc. in the Environmental Health risk assessment, China resident exposure parameter is inquired into [J]. the .2009 of Research of Environmental Sciences (10): 1164-1170.

Claims (9)

1. the health risk predicting and appraising method of methenyl choloride in a water supply network, is characterized in that, comprises as the next stage:

1) choose three class water nodes in the potable water water supply network, to different node serial samplings, measured methenyl choloride concentration, chlorine consumption, total organic carbon, water temperature, pH value, SUVA value and ammonia nitrogen concentration in each Nodes water in 1 year;

2) set up the calculation risk model of methenyl choloride, comprise the independent variable index is carried out principal component analysis, and carry out the logistic regression modeling;

3) carry out health risk assessment, comprise the steps:

(1) determine judgement schematics and computing method;

(2) according to the pipe network water body carcinogenic risk under the different route of exposure of step (1) calculating;

(3) according to the methenyl choloride hazard index under the different route of exposure of step (1) calculating;

(4) carry out the health risk assessment of ductwork water quality.

2. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, is characterized in that the stage 1) described in three category nodes be respectively residential node, office type node and communal facility type node.

3. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, it is characterized in that, stage 1) in, the assay method of methenyl choloride is to adopt improved U.S. EPA 502.2 methods, namely uses the vapor-phase chromatography of liquid-liquid extraction method and having electronic acquisition detector.

4. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, it is characterized in that, stage 2) the calculation risk model of setting up methenyl choloride described in is, at first, carry out principal component analysis with chlorine consumption, total organic carbon, water temperature, pH value, SUVA value and the ammonia nitrogen concentration that detects as the independent variable index, characterize original independent variable information with contribution rate of accumulative total greater than three major components of 0.7.Then, be concentration≤60 μ g/L according to the index request to methenyl choloride in drinking water sanitary standard, set the criterion of binary variable: when methenyl choloride concentration≤60 μ g/L, node methenyl choloride concentration safety, binary variable Alarm=0; When methenyl choloride concentration〉during 60 μ g/L, the methenyl choloride risk appears in node, binary variable Alarm=1.At last, use the logistic regression method to set up the logical relation of three major components and node methenyl choloride risk, obtain the calculation risk probability model of node methenyl choloride:

$P=\frac{\mathrm{EXP}(-i-f_1\&times;\mathrm{Prin}1-f_2\&times;\mathrm{Prin}2-f_3\&times;\mathrm{Prin}3)}{1+\mathrm{EXP}(-i-f_1\&times;\mathrm{Prin}1-f_2\&times;\mathrm{Prin}2-f_3\&times;\mathrm{Prin}3)}$

In formula, P is the calculation risk probable value of methenyl choloride, and Prin1, Prin2 and Prin3 are respectively contribution rate of accumulative total and reach numerical value greater than the major component more than 0.7, carry out i, f in SAS software ₁, f ₂And f ₃Recurrence calculate, the regression result that obtains model parameter is: i=4.5336, f ₁=-0.5665, f ₂=0.8971, f ₃=-0.3649.

After completing the model parameter recurrence, calculate the risk probability of respectively organizing the corresponding methenyl choloride of testing result of water quality independent variable index, and the CONCENTRATION DISTRIBUTION situation of methenyl choloride under each risk probability is made statistics.

5. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, is characterized in that the stage 3) described in judgement schematics be:

(a) the methenyl choloride carcinogenic risk=CDIoral take the diet absorption as route of exposure * PForal

$\mathrm{CDIoral}=\frac{\mathrm{CW}\&times;\mathrm{IR}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

In formula:

The potential carcinogen of PForal---specific carcinogen take the diet absorption as route of exposure characterizes the effect of carcinogenicity, with reference to the numerical value that Environmental Protection Agency and U.S.'s integrated risk infosystem provide, gets 6.1 * 10 ^-3(mg/kg/day) ^-1

CDIoral---diet is taken in the chronic average daily uptake of methenyl choloride of approach, mg/kg/day;

CW---the methenyl choloride concentration in water, mg/L;

IR---day absorption water yield, L/day, the day water uptake of residential, office type and communal facility type Nodes is taken as respectively 3.5 ± 0.21L/day, 2.5 ± 0.11L/day and 1.5 ± 0.06L/day;

ED---individual open-assembly time, days, the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10 days and (270days/year * 71.4years) ± 15days;

BW---whose body weight, individual average weight are 58.70kg;

AT---individual mean lifetime, days, the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, is 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years;

(b) the methenyl choloride carcinogenic risk=CDIderm take skin contact as route of exposure * PFderm

$\mathrm{CDIderm}=\frac{\mathrm{CW}\&times;\mathrm{SA}\&times;\mathrm{PC}\&times;\mathrm{ET}\&times;\mathrm{EF}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

In formula:

The potential carcinogen of PFderm---specific carcinogen take skin contact as route of exposure characterizes the effect of carcinogenicity, and the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 6.1 * 10 ^-3(mg/kg/day) ^-1

CDIderm---the chronic average daily uptake of methenyl choloride take skin contact as approach, mg/kg/day;

CW---the concentration of methenyl choloride in water, μ g/L;

SA---the skin surface that can contact is long-pending, m ², the male sex gets 1.697m ², the women gets 1.531m ², be 105.20:100 by M-F, calculating mean value is 1.616m ²

PC---the permeability of the specific chemical pollutant of skin surface, m/h, the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 0.0020m/h;

ET---open-assembly time, h/event refers to expose duration at every turn, is taken as 0.2h/event;

EF---expose frequency, event/day, wherein EPA recommendation 1event/day is adopted in the residential block, and this value is statistic, and the exposure frequency of office type node is taken as 0.3 ± 0.05event/day, and communal facility type node is taken as 1.25 ± 0.15event/day;

ED---individual open-assembly time, day, the residential Nodes is got the recommendation 365days/year of Environmental Protection Agency * 71.4year, and the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days;

BW---whose body weight, Chinese male average weight 62.7kg, women's average weight 54.4kg are 105.20:100 according to M-F, calculating individual average weight is 58.70kg;

AT---individual mean lifetime, days, the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, is 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years.

(c) the methenyl choloride carcinogenic risk=CDIinhalation take the steam suction as route of exposure * PFinhalation

$\mathrm{CDIinhalation}=\frac{\mathrm{CA}\&times;\mathrm{IR}\&times;\mathrm{ET}\&times;\mathrm{EF}\&times;\mathrm{ED}}{\mathrm{BW}\&times;\mathrm{AT}}$

$\mathrm{CA}=\frac{Q_W{P}_V\mathrm{CW}}{k_{a}V}(1-E^{-k_{a}t})\&times;{10}^{-3}$

In formula:

The potential carcinogen of PFinhalation---specific carcinogen take the steam suction as route of exposure characterizes the effect of carcinogenicity, and the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 6.6 * 10 ^-3(mg/kg/day) ^-1

CDIinhalation---the chronic average daily uptake of methenyl choloride take the steam suction as approach, mg/kg/day;

CA---the concentration of methenyl choloride in water vapor, mg/m ³

IR---suck speed, m ³/ h, the male sex are 19m ³/ d, women are 14m ³/ d is 105.20:100 by M-F, and calculating mean value is 16.56m ³/ d, i.e. 0.69m ³/ h;

ET---open-assembly time, h/event is taken as 0.2h/event;

EF---expose frequency, event/day, wherein, the residential node adopts EPA recommendation 1event/day, and the exposure frequency of office type and communal facility type Nodes is taken as respectively 0.3 ± 0.05event/day and 0.75 ± 0.10event/day;

ED---individual open-assembly time, day, the open-assembly time of office type and communal facility type Nodes is got respectively (300days/year * 71.4year) ± 10days and (270days/year * 71.4years) ± 15days;

BW---whose body weight, Chinese male average weight 62.7kg, women's average weight 54.4kg, M-F is 105.20:100, calculating individual average weight is 58.70kg;

AT---individual mean lifetime, days, the Chinese male mean lifetime is that, women's mean lifetime in 69.6 are 73.3, is 105.20:100 by M-F, calculating individual mean lifetimes is 365days/year * 71.4years.

Q _w---water velocity, get 10L/min; P _V---the conversion ratio of methenyl choloride from water to the air, get 8.76%; CW---the concentration of methenyl choloride in water, μ g/L; V---volume per capita during shower is got 2m ³k _a---air exchange rate during shower, get 0.021; T---the shower time, get 12min;

(d) the methenyl choloride hazard index under different route of exposure, computing formula is as follows:

Methenyl choloride hazard index=CDIoral/RfD take the diet absorption as route of exposure

Methenyl choloride hazard index=CDIderm/RfD take skin contact as route of exposure

In formula:

RfD---characterize the reference dose of the non-carcinogenic dangerous effect of predetermined substance, mg/kg/day, the numerical value with reference to Environmental Protection Agency and U.S.'s integrated risk infosystem provide is taken as 1.0 * 10 ^-2Mg/kg/day;

CDIoral---diet is taken in the chronic average daily uptake of methenyl choloride of approach, mg/kg/day;

The chronic average daily uptake of the methenyl choloride of CDIderm---skin contact approach, mg/kg/day.

6. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, is characterized in that the stage 3) in (1) described computing method be following steps:

(1) according to the water quality detection record of each node chlorine consumption, total organic carbon, water temperature, pH value, SUVA and ammonia nitrogen, the data value of simulating the water-quality guideline of described each node chlorine consumption, total organic carbon, water temperature, pH value, SUVA and ammonia nitrogen with monte carlo method;

(2) according to the stage 2) in the result of the principal component analysis (PCA) that obtains, adopt the Monte Carlo simulation result of chlorine consumption, total organic carbon, water temperature, pH value, SUVA and six model independent variable indexs of ammonia nitrogen, calculate the concrete numerical value of three major components, and in conjunction with the stage 2) in the formula that provides $P=\frac{\mathrm{EXP}(-i-f_1\&times;\mathrm{Prin}1-f_2\&times;\mathrm{Prin}2-f_3\&times;\mathrm{Prin}3)}{1+\mathrm{EXP}(-i-f_1\&times;\mathrm{Prin}1-f_2\&times;\mathrm{Prin}2-f_3\&times;\mathrm{Prin}3)}$ Completing the methenyl choloride risk probability calculates;

(3) take the middle gained methenyl choloride risk probability result of calculation of step (2) as the basis, according to the stage 2) in methenyl choloride CONCENTRATION DISTRIBUTION corresponding to different risk probabilities that get of the calculation risk model of methenyl choloride, with monte carlo method simulate in step (2) the corresponding methenyl choloride concentration of risk probability numerical value;

(4) with the methenyl choloride concentration numerical value of step (3) gained, bring the stage 3 into) in methenyl choloride carcinogenic risk, hazard index formula under given each route of exposure, thereby complete calculating.

7. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, it is characterized in that the stage 3) described in different approaches under pipe network water body carcinogenic risk comprise: the cancer risk take the diet absorption as route of exposure, the cancer risk take skin contact as route of exposure and the cancer risk take the steam suction as route of exposure.

8. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, it is characterized in that the stage 3) described in the methenyl choloride hazard index of different approaches include: diet is taken in the methenyl choloride hazard index of approach and the methenyl choloride hazard index of skin contact approach.

9. the health risk predicting and appraising method of methenyl choloride in water supply network according to claim 1, it is characterized in that, stage 3) health risk assessment of carrying out ductwork water quality described in is, pipe network water carcinogenic risk under the different route of exposure that calculate and methenyl choloride hazard index are the basis, by with the human health risk assessment guide rule of Environmental Protection Agency issue in material carcinogenic risk grade and the risk index assessment criterion stipulated compare, estimate the health risk situation of pipe network water.

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