Distribution,source And Ecological Risk Assessment Of Organophosphate In The Water And Soil At Village Scale In Cold Region

Organophosphate esters(OPEs)are used as additives in flame retardants and plasticizers.In recent years,with the gradual elimination of polybrominated diphenyl ether(PBDEs)flame retardants,the application of organophosphorus flame retardants(OPFRs)continues to increase.Consequently,large amounts of OPEs enter the environment.But up to now,most of the studies about OPEs have focused on cities and their surrounding areas,while there is few study on OPEs in rural and remote areas.In order to study the pollution of OPEs in rural and remote areas,this research collected and analyzed environmental samples from cold area Shenzha,Tibet and Xiuyan,Liaoning.The level,composition,distribution and the correlation between OPEs and environmental factors were mainly studied,and the possible source of OPEs were further explored by principal component analysis-multiple linear regression(PCA-MLR).At last,the ecological risk assessment of OPEs was assessed.The main results of this study are as follows:(1)The concentrations of ∑OPEs in the rivers of Daling Village,Fengyuan Village and Goumen Village were 29.79–732.28 ng/L(mean: 257.37 ng/L,median:250.68 ng/L),41.46–118.98 ng/L(mean: 79.53 ng/L,median: 84.28 ng/L)and15.43–105.21 ng/L(mean: 46.27 ng/L,median: 39.27 ng/L),respectively.TBEP,EHDPP and TEHP are the main OPEs in Daling Village;Ti BP,TCEP and TCPP are the main OPEs in Fengyuan Village;TCPP,TCEP and EHDPP are the main OPEs in Goumen Village.TCEP,TCPP and EHDPP are widely distributed in rivers in Xiuyan area.The results show that the OPEs pollution in rivers of the three villages have some similar characteristics,but also geographical differences,which may be related to the different industry type and economic development of the three villages.(2)The concentrations of ∑OPEs in soils of Daling Village,Huangdi Village,Goumen Village and Fengyuan Village were 1.92–10.16 ng/g(mean: 4.85 ng/g,median: 3.90 ng/g),4.84–12.37 ng/g(mean: 8.41 ng/g,median: 8.47 ng/g),6.99–32.87ng/g(mean: 19.46 ng/g,median: 18.73 ng/g)and 3.40–15.32 ng/g(mean: 7.70 ng/g,median: 5.88 ng/g),respectively.TCEP and TCPP are the dominant OPEs in soil of Daling Village;TCEP and TCPP are the dominant OPEs in the soil near the pig farm of Huangdi Village;TCEP and TEP are the dominant OPEs in soil near the pig farm of Goumen Village,and TCEP is the dominant OPEs in soil of Fengyuan Village.TCEP is the main OPEs in the soil samples of four villages in Xiuyan,Liaoning Province,with the highest concentration and 100% detection frequency.(3)∑OPEs concentrations in water samples of Shenzha,Tibet ranged from46.45–1744.73 ng/L(mean 289.18 ng/L,median 71.40 ng/L).∑OPEs concentration at SW-04 is the highest and much higher than other sites,which may be related to the long-term reception of domestic sewage at this site.The concentrations of ∑OPEs at the other seven sites ranged from 46.45–175.85 ng/L(mean 81.25 ng / L,median 71.06 ng / L).∑OPEs concentration in sediment samples ranged from 13.30–32.23 ng/g(mean 24.79 ng/g,median 28.41 ng/g).TCEP and TCPP are the main OPEs in river of Shenzha.EHDPP and TCEP are the main accumulated OPEs in the sediments of Shenzha,and the concentration of EHDPP was much higher than that of TCEP,so EHDPP was the main monomer of OPEs pollution in Shenzha.The concentration of OPEs in water and sediments samples was significantly affected by human activities.The concentration of OPEs near the county town was higher than that far away from the county town.(4)The concentration of ∑OPEs ranged from 29.74 ng/g–73.85 ng/g(mean 50.80ng/g,median 62.01 ng/g)at 16 sites in Shenzha,Tibet.EHDPP was the dominant OPEs in Shenzha.The concentration of OPEs in soil was affected by human activities.Generally speaking,the concentration of OPEs was higher near the densely populated area and lower far away from the densely populated area.However,the concentration of OPEs was higher in some places far away from the densely populated area,which indicated that there may be other potential sources affecting the distribution of OPEs in soil of Shenzha.(5)In river of Shenzha,Tibet,TN and TP had strong positive correlation with TCPP,TCEP and TDCIPP;TBEP had strong negative correlation with turbidity;EHDPP had strong positive correlation with COD and strong negative correlation with temperature.In rivers of villages in Xiuyan,Liaoning,Ti BP,Tn BP and TCEP had a strong positive correlation with SPC and turbidity,and turbidity also had a moderately strong positive correlation with TCPP,but there was no significant correlation between OPEs and TN,TP and COD.The different correlations between OPEs and environmental factors in the surface water of Shenzha,Tibet and villages of Xiuyan,Liaoning may be related to the differences in pollutant emissions and human activities.In soil of villages in Xiuyan,Liaoning,there was a moderately strong correlation between TCEP and TN,TP;in soil of Shenzha,Tibet,TCPP had a strong correlation with TN and TP,and TCEP had a strong correlation with TP,which indicating soil with higher nitrogen and phosphorus content may be more prone to the accumulation of TCEP and TCPP.(6)The water OPEs in villages of Xiuyan,Liaoning mainly came from architectural decoration and polyvinyl chloride,polyurethane foam and coatings,electronic products and transportation.The soil OPEs in villages of Xiuyan,Liaoning were mainly derived from vinyl polymers and electrolytes(contribution rate: 32.98%),polyurethane foam and coating(36.80%),electronic products and transportation(30.22%).Electronic products and traffic emission sources are the common source of OPEs in the water and soil of villages in Xiuyan,Liaoning.The water OPEs in Shenzha,Tibet was mainly derived from polyurethane foam,cellulose ester/lacquer/natural rubber/vinyl resin/transportation and building furniture.The soil OPEs in Shenzha,Tibet was mainly derived from vinyl polymer/electrolyte/polyurethane foam(contribution rate: 3.11%),building decoration(47.89%),electronic products and transportation(34.07%),and polyvinyl chloride(14.93%).Polyurethane foam,building decoration and traffic emission sources were the common sources of OPEs in the water and soil of Shenzha,Tibet.Polyurethane foam and traffic emission sources were the common pollution sources of villages in Xiuyan,Liaoning and Shenzha,Tibet,indicating that the production and use of polyurethane foam and traffic emissions may be important ways for OPEs to migrate to the environment.(7)In rivers of Xiuyan,Liaoning,the ecological risk of chronic exposure to OPEs was low;the ecological risk of acute exposure to OPEs of Fengyuan Village and Goumen Village was low,but,the ecological risk of acute exposure to water EHDPP,TBEP and TEHP of some sites in river of Daling Village was moderate.In soil of Xiuyan,Liaoning,the ecological risk of acute and chronic exposure to OPEs was both low.In river of Shenzha,Tibet,the ecological risk of acute and chronic exposure to OPEs was low.In soil of Shenzha,Tibet,the ecological risk of chronic exposure to OPEs was low,but EHDPP had moderate acute ecological risk in a large range(RQ0.13–0.37).