| As a new kind of resource, reclaimed water is gradually being used to a wide range of areas. However, with the increasingly close ties between people’s lives and recycled water, how to safely use it becomes the subject of heated debate. In view of this problem, combined with the use of reclaimed water irrigation, conducted a health risk assessment studies in order to provide scientific support for the safe use of recycled water.This study by thermal desorption-gas chromatography-mass spectrometry, measuring 2014-2015, and some northern cities using reclaimed water for irrigation of the Park and golf course of volatile organic compounds (VOCs), Using a four-step method to evaluate the health risks of 2014-November-Golf-Course of VOCs; at the same time,using improved Monte-Carlo method for health risk assessment evaluation of the carcinogenic risk of 2014 and 2015, Golf Course and TAORANTING-Park of VOCs.So that we carried out a scientific conclusion of wether or not volatile organic compounds which from reclaimed water into the air having on the human health risk assessment of the health of body.Results indicate thatQualitative and quantitative determination of volatile organic compounds and their content of the lawn after using reclaimed water for irrigation in TAORANTING Park, July 2014 to November2014 and April 2015 to October2015. Main substance found there are two types of aromatic and halogenated hydrocarbons. Aromatic 7 kinds:toluene, Ethylbenzene, xylene, styrene, methyl benzene, naphthalene; halogenated hydrocarbons 2 kinds:perchlorethylene, 1,4-dichlorobenzene. The cancer risks of substances:tetrachloroethylene-dichlorobenzene and naphthalene,1,4-Ethylbenzene. Quantitative analysis concluded that 2014-2015 Park recycled water blank value total volatile organic compounds in 80ng/L-110ng/L; 0.5-1.5 hours after irrigation, total volatile organic compounds content for 90ng/L-150ng/L. Typically,0.5 hours of irrigation with reclaimed water measurements of volatile organic compounds for maximum total, while the material reaches a maximum at 0.5 hour; another few cases 1.5 hours total reaches a maximum. Monitoring on the volatile organic compound content of maximum irrigation occurs after 3 hours of content and irrigation and tends to a blank value is less than the value. Lawn of the present test of volatile organic compounds due to the use of reclaimed water for irrigation and a significant increase in transpiration effect decreases over time.2. Qualitative and quantitative determination of volatile organic compounds and their content after golf courses use reclaimed water for irrigation of July 2014 to November 2014 and April, July, September and December of 2015. Qualitative detection of 20 kinds of volatile organic compounds (VOCs). Consists of olefin, aromatic hydrocarbons, halogenated hydrocarbons. Aromatic and 9 species of mainly toluene, ethyl benzene,1-methyl-ethyl-benzene, m, p-xylene,1,3,5-trimethyl benzene, Ortho-xylene, styrene, 1,2,4--trimethyl benzene, naphthalene. Halogenated hydrocarbons and 11 species of mainly six chlorine butadiene, tctrachloroethylene,1,1,2-three-chloroethane,1,4-p-dichlorobenzene, and,1,2-Ⅱ 1,3--dichlorobenzene p-dichlorobenzene,1,2,4-three-three chlorobenzene, chlorobenzene and 1,2,3-1,3,5-of trichlorobenzene,1,2--dibromo-chloropropane,1,1-two bromo-chloro-propane. Quantitative test results: 2014-2015 Stadium reclaimed water for blank values for total volatile organic compounds 80ng/L-120ng/L,0.5-2 hours after irrigation, total volatile organic compounds content for 110ng/L-150ng/L. Reclaimed water irrigation after 0.5 hour,1.5 hours total measurements of volatile organic compounds for maximum material reaches a maximum at 0.5 hour,1.5 hours. Monitoring on the volatile organic compound content of maximum irrigation occurs after 3 hours of content and irrigation and tends to a blank value is less than the value. This indicates that in the Green Golf ground, volatile organic compounds after irrigation with reclaimed water from spilling over into the air and reaches a maximum in the reclaimed water, it can be assumed for between-1.5 hours of irrigation.3. Select the November 2014 maximum evaluation as risk factors, using the four-step method for health risk assessment. Results showed that VOCs health risks significantly affected by irrigation. Non-cancer risk higher than the cancer risk, total cancer risk cannot be ignored, and at an acceptable level (10-7).4.In the usage of a software called "Crystal ball"which is based on Monte-Carlo method, we measured the content of VOCs which are from water to the air 0.5 hours after irrigation,2014 and 2015 gained from both TAORANTING-Park and Golf course. We calculated the probability distribution of corresponding content. And calculated carcinogenic risk of the selection of the carcinogenic risk of four kinds of material:tetrachloro ethylene, ethylbenzene,1,4-dichlorobenzene and naphthalene. Result showed that in TAORANTING-Park,90% chance of the highest total cancer risk was 2.88×10-8,which is higher than the neglected level(10-8), but still far below the acceptable level(10-6), so that we can’t neglect some potential risks in there.And that in Golf course,90% chance of the highest total cancer risk was 5.33 ×10-9,which is lower than the neglected level(10-8), so that we can neglect some potential risks in there.Above,we monitored the volatile organic compounds (VOCs) in air in the lawn which is irrigated by reclaimed water,both in TAORANTING Park and Golf Course. VOCs we found and were detected in two major categories of a total of 22 kinds of volatile organic compounds. Among them, in two experiments were detected in the aromatic hydrocarbon have six, toluene, ethylbenzene, xylene,1,3,5 trimethyl benzene, xylene and styrene; halogenated hydrocarbons has 6 kinds of chloroform, tetrachloroethylene,1,1,2-trichloro ethane,1,4-dichlorobenzene,1,3 dichlorobenzene and 1,2,4 trichloro toluene. The maximum content of 200ng/L (November 2014) was found in the quantitative analysis. The content of volatile organic compounds in reclaimed water was 0.5 hours after irrigation as peak or inflection point. Of the maxima of the deterministic health risk assessment found that health risks at an acceptable level; to 2014,2015 Park and golf course irrigation 0.5 hours of data were based on Monte Carlo method of uncertainty analysis, it is found that 90% probability highest total carcinogenic risk of carcinogenic risk is negligible level. Therefore, its health risks can be ignored. |
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