Construction method of surface water environment priority pollutant list
阅读说明：本技术 一种地表水环境优先污染物清单的构建方法 (Construction method of surface water environment priority pollutant list ) 是由 龚雄虎 赵中华 丁琪琪 金苗 张路 于 2021-07-08 设计创作，主要内容包括：本发明公开了一种地表水环境优先污染物清单的构建方法,根据污染物实测环境浓度,囊括化合物毒性基本参数及受纳水环境生态及人体健康风险,采用科学权重赋分方法,建立地表水环境特定的优先污染物清单,评估化学品对地表水环境和流域人类健康的潜在危害。本发明的方法解决了现有优先污染物筛选过程中存在的缺乏科学评估或者评估体系不够科学全面的问题,可避免仅考虑污染物的产量、排放量或通过模型预测环境中污染物浓度而带来的不确定性。(The invention discloses a method for constructing a list of surface water environment priority pollutants, which comprises the steps of according to the actually measured environmental concentration of pollutants, including basic toxicity parameters of compounds and the ecological and human health risks of a received water environment, adopting a scientific weight assigning method to establish a list of surface water environment specific priority pollutants, and evaluating the potential hazards of chemicals to the surface water environment and the human health of a drainage basin. The method solves the problems that the prior pollutant screening process lacks scientific evaluation or an evaluation system is not scientific and comprehensive enough, and can avoid the uncertainty caused by only considering the output and the discharge of pollutants or predicting the pollutant concentration in the environment through a model.)
1. A construction method of a surface water environment priority pollutant list is characterized by comprising the following steps:
step one, establishing a pollutant primary screening library; pollutants in the primary screening library are selected from traditional persistent organic pollutants, emerging pollutants, volatile organic pollutants and inorganic metal elements, and are constructed by combining the chemical classes of key concern at home and abroad, the book of names of priority control chemicals published by the department of ecological environment in China and the common characteristic pollutant classes and literature data in the environmental quality standard GB3838-2002 of surface water in China;
step two, constructing an index evaluation system of the pollutants based on the following indexes:
environmental exposure level, measured as concentration of contaminant in the environmentcAnd the detection frequency ODFCharacterizing;
the persistence of the pollutants in the environment is characterized by a biodegradation coefficient BioWIN of the pollutants obtained by an EPI Suite model;
biological accumulation of contaminants, n-octanol Water partition coefficient K obtained by using EPI Suite modelowCharacterizing;
the ecological risk of the pollutant is represented by ecological risk entropy RQ of the pollutant;
the human health risk of the pollutants is characterized by a lifetime carcinogenic risk index ILCR if the pollutants are carcinogens, or by a hazard index HI if the pollutants are carcinogens;
thirdly, carrying out quantitative characterization on each index in the second step based on the measured data and the chemical compound property;
step four, grading and assigning each index according to the result obtained in the step three;
fifthly, giving weights to all the parameters according to all the parameter scores obtained in the step four to calculate comprehensive scores of pollutants;
and step six, dividing the comprehensive scores of all pollutants into five grades I-V by using a geometric classification method, and listing the I-grade pollutants to construct a priority pollutant list.
2. The method of claim 1, wherein the persistent organic pollutants of the traditional type comprise polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs), and Polycyclic Aromatic Hydrocarbons (PAHs);
the emerging pollutants include phthalate esters (PAEs), Antibiotics (ANTs), Bisphenols (BPs), perfluorinated compounds (PFCs), Brominated Flame Retardants (BFRs), organic phosphorus flame retardants (OPEs), Chlorinated Paraffin (CPs) and Pharmaceutical and Personal Care Products (PPCPs).
3. The method of claim 1, wherein the measured concentration of the pollutant in the environment is characterized by a dispersion normalized value of the measured concentration of the pollutant in the water environment;
the pollutant detection rate is the detection frequency of a certain pollutant in all sampling points.
4. The method according to claim 1, wherein the ecological risk entropy RQ is a ratio of a measured concentration of a pollutant in an aqueous environment and a predicted non-stress concentration, the predicted non-stress concentration being calculated based on:
(1) when the toxicity data of the screened pollutants meets the requirement that the species at least cover 3 nutrition levels and the species at least contain 5, a species sensitivity distribution curve method SSD is selected to derive the predicted non-effect concentration PNEC as follows:
wherein HC5 (chronic)Chronic toxicity data, ng/L, to protect 95% of species from impact; AF is an evaluation factor, the value of AF is between 1 and 5, and HC is deduced5Is related to uncertainty of;
when the chronic toxicity data of the contaminants is insufficient to construct the SSD, it is deduced by the following acute toxicity data of the contaminants:
wherein HC5 (acute)Acute toxicity data to protect 95% of species in the ecosystem from impact; ACR is acute and chronic toxicity ratio, and the geometric mean value of the acute and chronic toxicity data ratio of 3 or more species is usually adopted as ACR, if ACR cannot be deduced, 10 is adopted as the default value of ACR;
(2) when the toxicity data of the screened pollutants do not meet the condition (1), an evaluation factor method is selected to calculate the PNEC, and the calculation method comprises the following steps:
wherein NOEC is the concentration of ineffective response of chronic toxicity data, ng/L; LC (liquid Crystal)50Semi-lethal concentration, ng/L, for acute toxicity data; EC (EC)50Ng is the maximum half-effect concentration of the acute toxicity dataL；
If the pollutant toxicity data includes NOEC, then derive PNEC with NOEC, otherwise use LC50Or EC50Derivation; the specific selection principle of AF refers to European Union technical guide rules, and the values are assigned to 10, 50, 100 or 1000 according to the composition condition of toxicity data.
5. The method of claim 1, wherein the drinking water and skin exposure routes are selected to calculate the lifetime carcinogenic risk index ILCR and the non-carcinogen hazard index HI.
6. The method according to claim 1 or 5, wherein the lifetime carcinogenic risk index ILCR is calculated by:
a. calculating daily exposure dose ADD of drinking water path of pollutants respectivelydriADD exposed to human skin at daily doseder：
Wherein MEC is the actually measured concentration of pollutants in the water environment, ng/L; IR is drinking water intake, mL/d; EF is exposure frequency, 350 d/a; ED is the exposure period, a; BW is body weight, kg; AT is the average exposure time, d;
wherein SA is the skin contact surface area, cm2(ii) a PC is the skin permeation constant of chemical substances, cm/h; ET is exposure time, h/d; CF is a conversion factor, 10-9；
b. For carcinogens, the lifetime carcinogenic risk index ILCR was calculated as follows:
ILCR＝ADDdri×SFdri+ADDder×SFder
wherein, SFdriAnd SFderRespectively as drinking water and skin exposureCarcinogenic slope factor of (mg/(kg. d))-1。
7. The method according to claim 1 or 5, wherein the non-carcinogen hazard index HI is calculated for non-carcinogens by:
wherein, RfDdriAnd RfDderReference doses for long-term intake, mg/(kg. d), in the drinking and skin exposure routes, respectively.
8. The method according to claim 1, wherein in the fourth step, each parameter is classified and assigned in the following manner:
i, defining classification standard by geometric classification method and geometric progression to obtain index parameters O of pollutantsc，ODF，BioWIN，KowRQ, HI and ILCR are divided into 5 equal ratio intervals according to the size and respectively correspond to 5 grades;
and II, assigning scores to the 5 grades through an 2/3 cumulative rank ordering method to obtain the parameter score of each index.
9. The method according to claim 1 or 8, wherein in the fourth step, for O-containing compoundscAnd ODFAnd taking the average value of the two characterization quantities as the parameter score of the index.
10. The method according to claim 1, wherein in the fifth step, each parameter is given equal weight.
Technical Field
The invention belongs to the technical field of environmental science, and particularly relates to a construction method of a surface water environment priority pollutant list.
Background
In recent years, with the rapid development of social economy, the environmental pollution problem caused by the use and discharge of a large amount of chemicals is increasingly prominent. By incomplete statistics, CAS registry chemicals were over 1.7 billion at the end of 2020, with a 25% annual growth rate from 2013, increasing by 4 million per day. Such numerous chemicals enter the environment and disrupt the original balance of the ecosystem, especially some toxic and harmful pollutants, as well as have persistent, bioaccumulative and carcinogenic, teratogenic, mutagenic effects and endocrine disrupting effects. After entering the water environment, chemicals can be transferred through a medium and a food chain to cause potential harm to aquatic ecosystems and human health. Because the pollutants are various and cannot be monitored and controlled comprehensively, how to screen and identify the potentially harmful priority pollutants from numerous chemicals is the key of water pollution prevention and control.
At present, China still has some defects in the process of constructing a surface water environment priority pollutant list: (1) the selected parameters and models mostly refer to foreign schemes directly, and model parameters and scoring standards aiming at the local actual environmental conditions of China are lacked; (2) the method mainly screens the priority pollutants according to expert experience, and has strong subjectivity; (3) the screening indexes are not comprehensive enough, and the human health exposure risk caused by pollutants is not considered. Therefore, it is necessary to establish a multi-index and quantitative screening method for surface water environment priority pollutants to construct a list of surface water environment priority pollutants.
Disclosure of Invention
The invention aims to provide a method for constructing a multi-index and quantitative surface water environment priority pollutant list.
In order to achieve the technical purpose, the invention adopts the following technical scheme:
a construction method of a surface water environment priority pollutant list comprises the following steps:
step one, establishing a pollutant primary screening library; pollutants in the primary screening library are selected from traditional persistent organic pollutants, emerging pollutants, volatile organic pollutants and inorganic metal elements, and are constructed by combining the chemical classes of key concern at home and abroad, the book of names of priority control chemicals published by the department of ecological environment in China and the common characteristic pollutant classes and literature data in the national surface water environment quality standard GB 3838-2002;
step two, constructing an index evaluation system of the pollutants based on the following indexes:
environmental exposure level, measured as concentration of contaminant in the environmentcAnd the detection frequency ODFCharacterizing;
the persistence of the pollutants in the environment is characterized by a biodegradation coefficient BioWIN of the pollutants obtained by an EPI Suite model;
biological accumulation of contaminants, n-octanol Water partition coefficient K obtained by using EPI Suite modelowCharacterizing;
the ecological risk of the pollutant is represented by ecological risk entropy RQ of the pollutant;
the human health risk of the pollutants is characterized by a lifetime carcinogenic risk index ILCR if the pollutants are carcinogens, or by a hazard index HI if the pollutants are carcinogens;
thirdly, carrying out quantitative characterization on each index in the second step based on the measured data and the chemical compound property;
step four, grading and assigning each index according to the result obtained in the step three;
step five, according to the scores of all the parameters obtained in the step four, giving the same weight to all the parameters to calculate the comprehensive score of the pollutants
And step six, dividing the comprehensive scores of all pollutants into five grades I-V by using a geometric classification method, and constructing a priority pollutant list by using the I-grade pollutants.
As a further improvement of the invention, the traditional persistent organic pollutants comprise polychlorinated biphenyl PCBs, organochlorine pesticides (OCPs) and Polycyclic Aromatic Hydrocarbons (PAHs);
the emerging pollutants include phthalate esters (PAEs), Antibiotics (ANTs), Bisphenols (BPs), perfluorinated compounds (PFCs), Brominated Flame Retardants (BFRs), organic phosphorus flame retardants (OPEs), Chlorinated Paraffin (CPs) and Pharmaceutical and Personal Care Products (PPCPs).
The volatile organic pollutants VOCs comprise aromatic hydrocarbons and halogenated hydrocarbons.
As a further improvement of the invention, the actually measured concentration of the pollutant environment is characterized by a dispersion standardized value of the actually measured concentration of the pollutant in the water environment;
the pollutant detection rate is the detection frequency of a certain pollutant in all sampling points.
As a further improvement of the present invention, the ecological risk entropy RQ is a ratio of an observed concentration of a pollutant in a water environment to a predicted ineffective concentration, and the predicted ineffective concentration is calculated based on the following manner:
(1) when the toxicity data of the screened pollutants meets the requirement that the species at least cover 3 nutrition levels and the species at least contain 5, a species sensitivity distribution curve method SSD is selected to derive the predicted non-effect concentration PNEC as follows:
wherein HC5 (chronic)Chronic toxicity data, ng/L, to protect 95% of species from impact; AF is an evaluation factor, the value of AF is between 1 and 5, and HC is deduced5Is related to uncertainty of;
when the chronic toxicity data of the contaminants is insufficient to construct the SSD, it is deduced by the following acute toxicity data of the contaminants:
wherein HC5 (acute)Acute toxicity data to protect 95% of species from exposure; ACR is acute or chronic toxicity ratio, usually collectedUsing a geometric mean value of the acute and chronic toxicity data ratio of 3 or more species as ACR, and if ACR cannot be deduced, using 10 as a default value of ACR;
(2) when the toxicity data of the screened pollutants do not meet the condition (1), an evaluation factor method is selected to calculate the PNEC, and the calculation method comprises the following steps:
wherein NOEC is the concentration of ineffective response of chronic toxicity data, ng/L; LC (liquid Crystal)50Semi-lethal concentration, ng/L, for acute toxicity data; EC (EC)50Maximum half effect concentration, ng/L, for acute toxicity data;
if the pollutant toxicity data includes NOEC, then derive PNEC with NOEC, otherwise use LC50Or EC50Derivation; the specific selection principle of AF refers to European Union technical guide rules, and the values are assigned to 10, 50, 100 or 1000 according to the composition condition of toxicity data.
As a further improvement of the invention, the daily exposure dose of the drinking water route and the daily exposure dose of human skin contact are selected as quantitative parameters for calculating the indexes of the lifetime carcinogenic risk index ILCR and the non-carcinogenic hazard index HI.
As a further improvement of the invention, the lifelong carcinogenic risk index ILCR and the non-carcinogenic hazard index HI indexes are calculated in the following manner:
a. calculating daily exposure dose ADD of drinking water path of pollutants respectivelydriADD exposed to human skin at daily doseder：
Wherein MEC is the actually measured concentration of pollutants in the water environment, ng/L; IR is drinking water intake, mL/d; EF is exposure frequency, 350 d/a; ED is the exposure period, a; BW is body weight, kg; AT is the average exposure time, d;
wherein SA is the skin contact surface area, cm2(ii) a PC is the skin permeation constant of chemical substances, cm/h; ET is exposure time, h/d; CF is a conversion factor, 10-9；
b. For carcinogens, the lifetime carcinogenic risk index ILCR was calculated as follows:
ILCR＝ADDdri×SFdri+ADDder×SFder
wherein, SFdriAnd SFderCarcinogenic slope factor in the drinking water and skin exposure routes, (mg/(kg. d))-1；
For non-carcinogens, the hazard index HI is calculated as follows:
wherein, RfDdriAnd RfDderReference doses for long-term intake, mg/(kg. d), in the drinking and skin exposure routes, respectively.
As a further improvement of the present invention, in the fourth step, the classification and assignment of each parameter are as follows:
i, defining classification standard by geometric classification method and geometric progression to obtain index parameters O of pollutantsc，ODF，BioWIN，KowRQ, HI and ILCR are divided into 5 equal ratio intervals according to the size and respectively correspond to 5 grades;
and II, assigning scores to the 5 grades through an 2/3 cumulative rank ordering method to obtain the parameter score of each index.
As a further development of the invention, said four steps, for the O-containingcAnd ODFTaking two characteristic quantities as environmental exposure level indexes of the two characteristic quantitiesThe average value of (a) is used as the parameter score of the index.
As a further improvement of the present invention, in the fifth step, each parameter is given an equal weight.
The method has the advantages that the model derivation data is replaced by the received lake water environment chemical monitoring data, the threshold value method or the evaluation factor method is replaced by the probability ecological risk evaluation method to avoid the phenomenon of under-protection or over-protection, the chemical toxic characteristic parameters and the human health exposure risk are integrated, the multi-parameter comprehensive evaluation method is established to screen and identify the surface water environment priority pollutants, the unified methodological guidance is provided for the construction of the lake basin water environment priority pollutant list, and the scientific basis is provided for the lake formulation-basin priority pollutant emission and control standard.
Drawings
FIG. 1 is a flow chart of the method of the present invention.
Detailed Description
The technical scheme of the construction method of the surface water environment priority pollutant list is explained in detail below so as to better understand the technical scheme of the invention.
Take the construction of the prior pollutant list of the high post lake water environment in China as an example.
The method comprises the following steps: according to the chemical classes of the key concern at home and abroad, the name book of priority control chemicals published by the department of ecological environment in China and the common characteristic pollutant classes in the environmental quality standard (GB3838-2002) of surface water in China, and reference is made to literature data, 167 toxic and harmful chemicals are selected from the traditional classes of persistent organic pollutants, emerging pollutants, volatile organic pollutants and inorganic metal elements as a pollutant primary screening list. Traditional persistent organic pollutants include 18 polychlorinated biphenyls (PCBs), 20 organochlorine pesticides (OCPs) and 16 Polycyclic Aromatic Hydrocarbons (PAHs). Wherein PCBs include PCB77, PCB81, PCB105, PCB114, PCB118, PCB123, PCB126, PCB156, PCB157, PCB167, PCB169, PCB189, PCB28, PCB52, PCB101, PCB138, PCB153, and PCB 180. The OCPs include hexachloro (alpha-hexachloro, beta-hexachloro, gamma-hexachloro and delta-hexachloro), aldrin (aldrin, Dixon)Aldrin, endrin aldehyde and endrin ketone), endosulfans (alpha-endosulfan, beta-endosulfan and endosulfan sulfate), chlordanes (heptachloro, epoxy heptachloro, gamma-chlordane and alpha-chlordane), dichlors (p, p ' -dichlorous, p ' -dichlorous and p, p ' -dichlorous), and methoxychlor. PAHs include naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo (a) anthracene, perylene, and mixtures thereof,Benzo (b) fluoranthene, benzo (k) fluoranthene, benzo (a) pyrene, dibenzo (a, h) anthracene, benzo (g, h, i) perylene and indeno (1,2,3-c, d) pyrene. Emerging contaminants include 16 Phthalates (PAEs) and 50 Antibiotics (ANTs). Wherein the PAEs include dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, dimethoxyethyl phthalate, bis-4-methyl-2-pentyl phthalate, bis-2-ethoxyethyl phthalate, dipentyl phthalate, dihexyl phthalate, butylbenzyl phthalate, dibutoxyethyl phthalate, dicyclohexyl phthalate, di (2-ethyl) hexyl phthalate, diphenyl phthalate, di-n-octyl phthalate and dinonyl phthalate; ANTs include sulfonamides (sulfacetamide, sulfadiazine, sulfamethoxazole, sulfathiazole, sulfapyridine, sulfamethazine, sulfamethoxazole, sulfamethoxydiazine, sulfamethazine, sulfamonomethoxine, sulfamethazine, sulfachlorpyridazine, sulfaquinoxaline, sulfadimethoxine and trimethoprim), quinolones (ofloxacin, difloxacin, marbofloxacin, pefloxacin, sarfloxacin, norfloxacin, lomefloxacin, fleroxacin, enrofloxacin and ciprofloxacin), macrolides (erythromycin dehydrate, clarithromycin, norrithromycin, oleandomycin, tylosin, azithromycin and roxithromycin), tetracyclines (tetracycline, oxytetracycline, chlorotetracycline, doxycycline), chlorosilanes (chloramphenicol, florfenicol and thiamphenicol), Beta-lactam (cefalexin, ampicillin and amoxicillin), quinoxaline (carbalkoxy) and polyether ionophore antibiotics(monensin, salinomycin and narasin) and lincomycins (lincomycin and clindamycin). Volatile Organic Contaminants (VOCs) include aromatic hydrocarbons (toluene, ethylbenzene, p-xylene, o-xylene, styrene, cumene, n-propylbenzene, 1,2, 4-trimethylbenzene, 1,3, 5-trimethylbenzene, t-butylbenzene, sec-butylbenzene, p-isopropyltoluene and n-butylbenzene) and halogenated hydrocarbons (chlorobenzene, bromobenzene, 1,2, 2-tetrachloroethane, tetrachlorotoluene, 2-chlorotoluene, 1, 4-dichlorobenzene, 1, 3-dichlorobenzene, 1, 2-dibromo-3-chloropropane, 1,2, 4-trichlorobenzene, hexachlorobutadiene and 1,2, 3-trichlorobenzene). Inorganic metallic elements (HMs) include mercury, arsenic, cadmium, lead, chromium, beryllium, boron, aluminum, titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, selenium, molybdenum, silver, tin, antimony, barium, and thallium.
Step two: according to the existing research theory, consulting literature data and summarizing a criterion for screening the water environment priority pollutants by combining with actual investigation conditions, and constructing an index system; the index system contains the following 5 indexes. Index one is the environmental exposure level of the pollutant, and the environmental measured concentration (O) of the pollutant is comprehensively considered mainly through targeted analysisc) And the detected frequency (O)DF) (ii) a The second index is the persistence of the pollutant in the environment, the biological degradation coefficient (BioWIN) of the pollutant is obtained by using an EPI Suite model of the United states environmental protection agency (US EPA), and the environmental behavior and the biological degradation performance of the pollutant are evaluated; index three is the biological accumulation of pollutants, and the water distribution coefficient (K) of n-octanol obtained by using an EPI Suite modelow) Characterizing, and evaluating the bioaccumulation of the contaminants; the fourth index is the ecological risk of the pollutants, and the ecological risk of the pollutants in the water environment is quantitatively represented by referring to a risk entropy value method in European Union technical guidelines; and the fifth index is the human health risk of the pollutants, is determined by referring to a health risk model in a comprehensive risk information system of US EPA, and is used for respectively evaluating the non-carcinogenic risk and the carcinogenic risk.
Step three: acquiring each index parameter in the second step according to the measured data and the compound property:
acquiring the environmental exposure level of pollutants:
i-1 acquisition of pollutant concentration data:because the concentration difference of different types of pollutants is large, the concentration values of all the pollutants to be selected need to be normalized, and the concentration O of the pollutantscComprises the following steps:
wherein MEC represents the actually measured concentration of pollutants in the water environment, ng/L; MECmaxAnd MECminRepresenting the maximum and minimum concentration of all the contaminants chosen, ng/L, respectively.
Concentration data O of Gaoyou lake pollutantscThe value is between 0.0001 ng/L and 0.5562 ng/L.
I-2 contaminant detection Rate data ODFObtaining:
wherein, DF represents the detection frequency of the pollutants in all sampling points, and N is the total number of the sampling points.
High post lake pollutant detection rate data ODFThe value is between 4.8 and 100.
II, acquiring persistent data of pollutants: the biodegradation coefficient of a contaminant (BioWIN) is based on the epa EPI Suite model predictive value of USEPA, which predicts the environmental behavior of a contaminant and its biodegradability based on its physicochemical and environmental properties.
The BioWIN value of 167 pollutants is between 0.272 and 3.502.
III, a pollutant bioaccumulation score calculation method: the n-octanol water partition coefficient (K) of each pollutant was obtained by the EPI Suite model of US EPAow)。
K for 167 pollutantsowThe value is 2.51X 10-4～3.31×109In the meantime.
IV, acquiring ecological risk data of pollutants
The method for calculating the ecological risk entropy comprises the following steps: and (3) quantitatively representing the ecological risk of the pollutants in the water environment by referring to a risk entropy value method (RQ) in the technical guideline of European Union.
Wherein RQ is the ecological risk entropy of pollutants and is dimensionless; MEC is the actually measured concentration of the pollutants in the water environment, ng/L; PNEC was the predicted ineffective response concentration, ng/L.
The ecological risk RQ of the pollutants in the Gaoyou lake is 9.74 multiplied by 10-7～1.61×103In the meantime.
V, acquisition of pollutant human health risk data
Considering the exposure behavior and the exposure mode of human beings to the surface water environment, two ways of drinking water exposure and skin contact exposure are selected to evaluate the potential risks of pollutants on human health.
Daily exposure dose (ADD) for V-1 drinking pathwaydri) The calculating method of (2):
wherein MEC is the actually measured concentration of pollutants in the water environment, ng/L; IR is drinking water intake, mL/d; SA is skin contact surface area, cm2(ii) a BW is body weight, kg; AT is the average exposure time, d.
V-2 human skin exposure daily dose (ADD)der) The calculating method of (2):
wherein MEC is the actually measured concentration of pollutants in the water environment, ng/L; SA is skin contact surface area, cm2(ii) a PC is the skin permeation constant of chemical substances, cm/h; ET is exposure time, h/d; EF is exposure frequency, 350 d/a; ED is the exposure period, a; CF is a conversion factor, 10-9(ii) a BW is body weight, kg; AT is the average exposure time, d.
V-3 if the contaminant is a carcinogen, a life-long carcinogenic risk Index (ILCR) is used for health risk assessment, calculated as:
ILCR＝ADDdri×SFdri+ADDder×SFder
wherein, SFdriAnd SFderCarcinogenic slope factor in the drinking water and skin exposure routes, (mg/(kg. d))-1The parameters are derived from the USEPA's integrated risk information system data.
Gaoyouhu lifetime carcinogenic risk Index (ILCR) is 1.94X 10-7～2.05×10-1In the meantime.
V-4 if the contaminant is a non-carcinogen, health risk assessment is performed using the Hazard Index (HI) calculated as:
wherein, RfDdriAnd RfDderReference doses, mg/(kg. d), for long-term intake in the drinking and skin exposure routes, respectively, parameters were derived from the USEPA's comprehensive risk information system data.
The Gaoyouhu Hazard Index (HI) is 6.99 × 10-9～7.94×102In the meantime.
Step four: grading and assigning a score to each parameter according to the result obtained in the step three, wherein the calculation method comprises the following steps:
i, defining classification standard by geometric classification method and geometric progression to obtain index parameters O of pollutantsc，ODF，BioWIN，KowRQ, HI, ILCR are divided into 5 equal-scale intervals by size and correspond to 5 levels, respectively. The geometric progression calculation method comprises the following steps:
an＝a0×qn
wherein, anIs the upper limit value of the nth stage interval; a is0Is the minimum value of the parameter; q is an equal ratio constant; n is 1,2,3,4, 5.
And II, assigning scores to 5 grades by referring to a USEPA (USEPA for general advice) demand method, namely converting the data by an 2/3 accumulated rank ordering method to obtain a parameter Score.
TABLE 1 grading and assigning of evaluation parameters
Equal ratio interval
Section class
Rank ordering
Cumulative rank ordering (COR)
(2/3)^(COR)
Score of
a4～a5
1
0
0
1.0000
100.00
a3～a4
2
1
1
0.6667
66.67
a2～a3
3
2
3
0.2963
29.63
a1～a2
4
3
6
0.0878
8.78
a0～a1
5
4
10
0.0173
1.73
III, the environmental exposure level of the pollutant comprehensively considers the actually measured concentration O of the pollutant in the environmentcAnd the detection frequency ODFTherefore, the environmental exposure level score (o) is calculated by:
wherein, Score (O)DF) Scoring the detection rate; score (O)c) The concentration score was detected.
Step five: and D, calculating a comprehensive score of the pollutants according to the scores of the parameters obtained in the step four and the equal weight of the parameters, and generating a characteristic pollutant score list according to the comprehensive score from high to low.
Score(T)＝Score(O)+Score(P)+Score(B)+Score(E)+Score(H)
Wherein score (o), score (p), score (b), score (e), score (h) and score (t) represent the environmental exposure level score, persistence score, bioaccumulation score, ecological risk score, human health risk score and composite score, respectively, of the contaminants.
TABLE 2 Gaoyou lake water body characteristic contaminant score List
The environmental detection rate of other 42 contaminants in Gaoyou lake is 0, so score (T) is 0, not included in the table.
Step six: the composite score for all contaminants is divided into five classes (I-V) using geometric classification, and a priority contaminant list is constructed with class I contaminants.
TABLE 3 Gaoyou lake water priority contaminant List
Numbering
Name of substance
CAS
Numbering
Name of substance
CAS
1
Diethylhexylphthalate
117-81-7
23
Methoxy chloride
72-43-5
2
Benzo (a) pyrene
50-32-8
24
PCB156
38380-08-4
3
Cis-chlordane
5103-71-9
25
PCB28
7012-37-5
4
Epoxy heptachloro
1024-57-3
26
PCB81
70362-50-4
5
PCB167
52663-72-6
27
Isodieldrin ketone
53494-70-5
6
Dinonyl phthalate
84-76-4
28
Dibenzo (a, h) anthracenes
53-70-3
7
Dieldrin agent
60-57-1
29
Phthalic acid bis-4-methyl-2-pentyl ester
146-50-9
8
Isodieldrin
72-20-8
30
Indeno (1,2,3-c, d) pyrene
193-39-5
9
Trans-chlordane
5103-74-2
31
Phthalic acid diisobutyl ester
84-69-5
10
Aishi agent
309-00-2
32
Dibutyl phthalate
84-74-2
11
p, p' -Didiyi
72-55-9
33
Beta-endosulfan
33213-65-9
12
Di-n-octyl phthalate
117-84-0
34
PCB153
35065-27-1
13
p, p' -drip
72-54-8
35
Alpha-endosulfan
959-98-8
14
PCB77
32598-13-3
36
Lead (II)
7439-92-1
15
PCB123
65510-44-3
37
PCB126
57465-28-8
16
Heptachlor
76-44-8
38
Aluminium
7429-90-5
17
Phthalic acid butyl benzyl ester
85-68-7
39
Iron
7439-89-6
18
Isodieldrin aldehyde
7421-93-4
40
Strontium salt
7440-24-6
19
p, p' -dichloro-diphenyl-trichloroethane
50-29-3
41
Diamyl phthalate
131-18-0
20
Copper (Cu)
7440-50-8
42
Phthalic acid dicyclohexyl ester
84-61-7
21
Barium salt
7440-39-3
43
Gamma-hexachloro cyclohexane
58-89-9
22
Dihexyl phthalate
84-75-3