Study On Distribution, Eco-toxicolological Effects And Health Risk Assessment Of Chlorophenol Contaminants In Dongting Lake

Chlorophenols(CPs) are a kind of toxic, refractory and widely used compoundsin industrial and agricultural production. Dongting Lake is a typical schistosomiasisendemic area. In order to kill the oncomelania, people had used a large number ofsodium pentachlorophenol(PCP-Na) in the early days,which cause the seriousenvironment pollution problems.The study in totally analyzes54bottles of surfacewater samples and9kinds of fish(59bottles of fish samples) in Dongting Lakeschistosomiasis endemic areas.The main results are as follows:(1) The surface water samples are analyzed in the following step:Enrichment–elution using HLB column, and then derivatized by BSTFA-TMCS, and detectedin GC/MS equipment.The results shows that the advantage of pollutants insurface water arepentachlorophenol,phenol,2-nitrophenol,2,4,6-trichlorophenol.The totalconcentration of phenol is575.95~785.82ng·L-1(geometric mean).The totalconcentration of chlorophenol is19.75~111.49ng·L-1,which the proportion of totalphenols is3.4%~15.1%.Comparing with2011,the total concentration of phenolin surface water is decreasing,which indicating the problem of water pollution hasimproved.(2) Chlorophenols are detected in all fish samples,and the average concentration ofchlorophenol is1.67~141.59ng·g-1(dry-weight,dw).The level of chorophenol isherbivorous> omnivorous> carnivorous in different trophic fish.The advantage ofpollutants in fish are pentachlorophenol (PCP, ΣPCP is234.65ng·g-1dry weight),2,3,5-trichlorophenol (2,3,5-TCP, Σ2,3,5-TCP is37.48ng·g-1dry weight).(3) The toxicological experiment shows that65%solubility powder sodiumpentachlorophenate has strongly toxicity to Japanese Medaka.It can induce therelated enzymes of Japanese Medaka’liver to result in oxidative damage(SODand CAT are significant changes).Lower concentration of PCP may interfere thethyroid endocrine system with fish.The results show that the level of total thyroxine(total T4) are significantly elevated, and the metabolism relatedgenes(dio1, dio2, sult1st5,ttr and ugt1ab) have significant changed.(4) Using EPA health risk assessment(HRA) model to assess the health risk of CPs tolocal people who live in Dongting Lake Area.The results show thatnon-carcinogenic risk and cancerous riskare both much less than the EPA’srecommended risk index(1,1.0×10-4).Therefore,the phenols in the surface waterdo not produce produce non-carcinogenic or carcinogenic hazards to DongtingLake region local people.