[Show abstract][Hide abstract] ABSTRACT: Organochlorine pesticides (OCPs) found in rivers from the Sichuan Basin to Aba Prefecture profile were analyzed to assess possible health risks to adults and children who use the river as a source of drinking water. OCP concentrations in surface water ranged between 22.29–274.28 ng·L−1. Compared with other published data around the world, OCP levels in this study were moderate. Among all OCPs, hexachlorobenzene (HCB) and hexachlorocyclohexanes (HCHs) were the predominant compounds. Higher concentrations of OCPs were attributed close to the agricultural fields of the Sichuan Basin, current OCPs inputs, and long-range atmospheric transport from abroad. Various spatial patterns of OCPs in the profile might be affected by the usage and physicochemical properties of the pesticides, in addition to the adjacent geographical environment. The health risk assessment indicated that most OCPs had little impact on human health according to the acceptable risk level for carcinogens (10−6) recommended by the US EPA. However, carcinogenic effects caused by heptachlor, Aldrin, HCB, and α-HCH might occur in drinking water. The risk of negative impacts caused by OCPs is much higher for children than for adults.
Full-text · Article · Jun 2015 · Frontiers of Earth Science
[Show abstract][Hide abstract] ABSTRACT: This study investigated the levels, sources and potential risks of polycyclic aromatic hydrocarbons (PAHs) in soil, water (dissolved phase, suspended particulate matter) and sediment along the Jinjiang River mainstream to Quanzhou Bay. The distribution coefficient of ΣPAHs varied disorderly along the Jinjiang River, indicating the non-equilibrium status for the partition. The various distribution features of ΣPAHs in the sediments of the north and south coast of Quanzhou Bay were probably due to the flow motions in the bay. High correlations of PAHs were found between different media, suggesting the approximately same source of PAHs. Furthermore, three source factors and their contributions were extracted using the positive matrix factorization model. Toxicity and biological risk were assessed using toxic equivalent quantity and sediment quality guideline quotient. The contamination of PAHs in the soil and sediments may turn to unconspicuous risks for the environment and humans except very few sites with moderate pollution.
Full-text · Article · Nov 2013 · Marine Pollution Bulletin
[Show abstract][Hide abstract] ABSTRACT: Totally 101 typical surface soil samples were collected from Daiyun Mountain Range, and 20 compounds of OCPs were analyzed by a Ni electron capture detector (GC-ECD) to investigate the horizontal distribution and composition of organochlorine pesticides (OCPs) in the surface soil of Daiyun Mountain Range. The results showed that all OCPs were detected in the soil samples. The detection ratios of OCPs were all over 90%, except for Endrin and beta-HCH. The sum concentration of HCHs, DDTs, Endosulfan and Endosulfan sulfate, accounted for 79.51% of the total OCPs, which were considered to be the dominant OCPs in the Daiyun Mountain Range. The OCPs concentrations in the surface soils ranged from 2.56 to 465.99 ng x g(-1) with a mean value of 38.00 ng x g)(-1). Compared with other regions, the concentrations of HCHs and DDTs in this study stayed in a low pollution level. Endosulfan and Endosulfan sulfate showed a certain degree of risk in the surface soil of the study area. Source analysis showed that new input of lindane and dicofol might occur in the survey region. The historical application was the prime source of Endosulfan. The residue level of OCPs in different lands was in the following order: paddy land > vegetable land > orchard. The OCPs pollution of orchard soil was primarily due to the new input of lindane and dicofol, while the pollution of paddy land was mainly from the usage of Endosulfan.
Full-text · Article · Nov 2013 · Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.]
[Show abstract][Hide abstract] ABSTRACT: A soil survey was conducted in Zhangzhou City, an important agricultural region in south of the Fujian Province, China. 93 surface soil samples were collected in the paddy fields, vegetable lands, orchards and tea plantations from Zhangzhou City. An additional soil profile was sampled in a paddy field as previous research had indicated high concentrations of organochlorine pesticides (OCPs) in the paddy fields. Dichlorodiphenyltrichloroethanes (DDTs) ranged from 0.64–78.07 ng g−1 dry weight and hexachlorocyclohexanes (HCHs) ranged from 0.72–30.16 ng g−1 dry weight in the surface soil of the whole study region. Ratios of α-HCH/γ-HCH < 4 and o, p′-DDT/p, p′-DDT > 1 in all soil samples suggested that lindane and dicofol were widely applied in this region in the past. Concentrations of HCHs and DDTs in soils from the four land use types followed the orders: paddy fields > vegetable lands > tea plantations > orchards and tea plantations > orchards > paddy fields > vegetable lands, respectively. Analyses of the data showed no correlation (r < 0.1) between elevation and OCPs contents in paddy fields, orchards and vegetable lands, indicated no significantly different features in distribution of HCHs and DDTs in the soils from low lying plains and mountains and the unsystematic usage of OCPs, and highlighted the fragmented nature of agricultural production in Zhangzhou, as well as the reemission of OCPs from the soils, where high OCPs concentrations were found, in Longhai of Zhangzhou. In addition, no obvious relationship between the OCPs and total organic carbon (TOC) (r < 0.3) was observed in the soil profile. The mean contribution of dicofol in total DDTs was 66% in the whole Zhangzhou region. The approximate burdens of HCHs and DDTs in the surface layer of 0–20 cm were 0.44 and 1.55 t, respectively. The storage of both HCHs and DDTs in soil surface layer (0–20 cm) accounts for 40% burden of the soil layer of 0–50 cm (1.10 t HCHs and 3.87 t DDTs), in which the highest concentrations of OCPs were observed in soil profile.
[Show abstract][Hide abstract] ABSTRACT: In order to understand atmospheric deposition of polycyclic aromatic hydrocarbons impact on ecological environment of Dashiwei Karst Tiankeng Group in Leye County, Guangxi (National Geological Park), the dry and wet deposition samples around Dashiwei Tiankeng were collected by season for a year, and were analyzed utilizing GC-MS for 16 EPA PAHs. The results showed that PAH depositional fluxes ranged from 132.36-1 655.27 ng x (m2 x d)(-1), with an average value of 855.00 ng x (m2 x d)(-1). Weight of PAHs which deposited into Dashiwei Tiankeng was 51.98 g x a(-1), and the dominant PAH compounds are benzo[b] fluoranthene, chrysene, benzo[a] pryene, benzo[k]fluoranthene, anthracene, phenanthrene and naphthalene. Spatial distribution of PAHs around Dashiwei Tiankeng was: the east valley entrance > the south valley entrance > the north valley entrance > the west peak; seasonal variability of PAH depositional fluxes was: spring > summer > autumn > winter. Deposition fluxes of PAHs were 4.6 times higher in spring and summer than those in autumn and winter. The dominant PAH compounds were 4-6 rings PAHs in spring and summer, but the dominant PAH compounds were 2-3 rings PAHs in autumn and winter. PAH depositional fluxes in this study area were closely related with precipitation, wind direction, temperature, wind speed and location of pollution sources. PAHs increased in spring and summer in Dashiwei Karst Tiankeng Group, this could be transported by atmospheric movement from higher air temperature and lower elevation areas where industry developed in Guangxi.
No preview · Article · Mar 2012 · Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.]
[Show abstract][Hide abstract] ABSTRACT: Surface soils from the Chengdu Economic Region (CER) were analyzed for sixteen United States Environment Protection Agency priority polycyclic aromatic hydrocarbons (PAHs) to study the spatial distribution and to identify the sources of PAHs. Relatively high concentrations (more than 1500ngg−1) of high molecular weight PAHs were found in Chengdu Plain, in the middle of CER, while high concentrations (more than 500ng g−1) of low molecular weight PAHs were detected in the surrounding mountains. The concentrations of ∑16-PAHs in topsoil samples from CER (12.52–75,431.47ngg−1, average value was 3233.92ngg−1) were higher than that from the southern China (21.91–3077ngg−1, average value was less than 500ngg−1), and they were comparable to concentrations in soils from the northern China (366–254,080ngg−1, mean value was more than 3000ngg−1). The concentrations from CER were also much higher than the concentrations of some world clean regions such as Antarctic (34.9–171ngg−1), European high mountains (9–11,000ngg−1, mean value was 158ngg−1) and some Europe residential (736ngg−1) and arable soils (60–145ngg−1, mean value was 66ngg−1). The ratio of tracer compounds (BaA/(BaA+Chr), Flo/(Flo+Pyr), and IcdP/(IcdP+BghiP)) indicated that the high concentrations of PAHs in soils were mainly derived from fossil fuels combustion in mountain region and from the incomplete combustion of petroleum in developed plain area (such as Chengdu and Deyang). From the above distribution characteristics and ratios of tracer compounds, we inferred the reasons for the distribution pattern of PAHs in CER were the domestic heating, emissions, and the physicochemical properties of PAHs.
Full-text · Article · Aug 2011 · Journal of Geochemical Exploration
[Show abstract][Hide abstract] ABSTRACT: In order to understand the composition, sources and contamination characteristics of PAHs in water from underground river of Dashiwei Tiankeng group in typical karst area located in Leye County, Guangxi. The water samples were collected from different sections to analyze 16 priority polycyclic aromatic hydrocarbons using GC-MS. The results showed that concentration of ∑PAHs (the total PAHs)in water ranges from 54.7 ng/L to 192.0 ng/L, with an average concentration of 102.3 ng/L. The predominant PAHs in water are 2-3 ring PAHs, accounting for 65.1% of ∑PAHs. The distribution of PAHs in water sampled along the underground river indicates that the mean concentration of ∑PAHs in upstream area is higher than that of downstream because of wastewater discharge. Meanwhile, the underground river has some adsorption effect to 4-6 ring PAHs. The concentration of ∑PAHs at Dashiwei Tiankeng section increases 93.8% attribute to the release of PAHs coming from karst environmental medium and/or atmospheric transmission in underground river system. However, the concentration of ∑PAHs at the confluence section of the tributary of Dashiwei Tiankeng is 47.3% less than that of the first upstream section duo to dilution. The concentration of ∑PAHs at Bailang outlet section is 128.3% and 17.8% higher than that of flow-in section and Dashiwei Tiankeng section respectively. The ratios of specific PAHs indicate that the PAH sources in Leye County and Dashiwei Tiankeng areas mainly come from both petroleum and its combustion. However, the petroleum origin comes from anthropogenic inputs in town and the natural inputs in Dashiwei Tiankeng. The PAH sources in rural areas are mainly originating from the combustion of grass, wood and coal. Comparison to other areas in the world, the ∑PAHs residual levels in underground river water in Dashiwei Tiankeng group is at the low level. In six sections, concentrations of benzo[a]pyrene(BaP) in surface water exceed the state quality standards.
No preview · Article · Apr 2011 · Huan jing ke xue= Huanjing kexue / [bian ji, Zhongguo ke xue yuan huan jing ke xue wei yuan hui "Huan jing ke xue" bian ji wei yuan hui.]
[Show abstract][Hide abstract] ABSTRACT: This study evaluated the contamination status and distribution of organochlorine pesticides (OCPs) between Xinghua Bay and adjacent watersheds in Putian region, southeast China. Twenty-five surface soil samples and two sediment cores were collected from two watersheds and the Xinghua Bay, respectively. Results showed that the concentrations of OCPs in samples of the Mulan River Watershed (MRW), the Qiulu River Watershed (QRW), the inner bay core (IBC) and the open bay core (OBC) were in the range of 4.96-38.20ng/g, 4.62-22.80ng/g, 1.84-80.46ng/g and 1.87-23.43ng/g, respectively. The mean concentration of OCPs was in an order: IBC>MRW>QRW>OBC. The higher concentration of OCPs in recent periods may suggest that a certain amount of OCPs were still input to this area.
Full-text · Article · Mar 2011 · Marine Pollution Bulletin
[Show abstract][Hide abstract] ABSTRACT: In order to study the levels and spatial distribution of organochlorine pesticides in soil samples from the Wuyi Mountains southern. The 30 soil samples were collected from the study area. The concentrations of OCPs in the samples were determined by GC-ECD with the internal standard method. The results showed that HCHs and DDTs were found widely in all samples and the concentrations of HCHs, DDTs in soils of the Wuyi Mountains were in the ranges of 1.14 - 30.62 ng g -1 (with a mean 5.04 ng g -1 ), 0.96 - 9.62 ng g -1 (with a mean 3.99 ng g -1 ), respectively. Compared to the reference data of Antarctic and Tebat area, the status of this area can be called "low pollution". Through source analysis�»�� -HCH and o,p`-DDT was the major source of HCHs, DDTs, respectively. The results indicated that HCHs in this area were historical application. But, new DDTs (dicofol) could be used recently in this area.
[Show abstract][Hide abstract] ABSTRACT: In order to assess the contamination of edible marine organisms in Quanzhou and Xinghua Bays, Fujian Province, China, concentrations of organochlorine pesticides (hexachlorocyclohexane isomers or HCHs and dichlorodiphenyltrichloroethane isomers/derivatives or DDTs) and heavy metals (Cu, Pb, Zn, As, Cr, Cd, Ni and Hg) in 13 species collected from different sites in the bays were analyzed by GC-ECD and ICP-MS. The concentration of the sum of DDTs exceeded that the sum of HCHs in the samples. Most of the organisms showed higher levels of DDTs than the first level criterion (10 ng/g) for marine biological quality in China (GB 18421-2001) but conformed to the first level criterion (20 ng/g) for HCHs. The estimated mean daily uptake of pesticides was below the level for minimal risk to the consumers. The levels of Cd, As and Pb in most organisms from both bays were markedly elevated and above the recommended legal limits for human consumption. Our results showed the need for routine monitoring of marine species contamination to ensure public and environmental health.
Preview · Article · Dec 2010 · Journal of Environmental Sciences
[Show abstract][Hide abstract] ABSTRACT: Soil samples collected from several sites along an altitudinal transect on the eastern slope of the Tibetan Plateau were analyzed for hexachlorobenzenes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs). The results showed that HCHs and DDTs were found in the soil samples from the remote high altitude areas away from source regions, which confirmed the long-range atmospheric transport phenomenon of these organochlorine pesticides (OCPs) insecticides. The OCP concentrations in the soils had a significant negative correlation with altitude; they showed a trend to increase with decreasing altitude, but the increase was not continuous, being interrupted at some moderate-altitude sites on the transect. The distances from the source region, landforms, soil properties, and physical-chemical properties of OCPs were more important than total organic carbon content to the distribution of OCPs in soils disturbed by human activities. An analysis of the compositions of HCH isomers and DDTs revealed predominantly low ratios of CK-HCH to 7-HCH, ranging from 0.06 to 4.79, which suggested current lindane inputs. On the other hand, low p,p'-DDT/p,p'-DDE and o,p'-DDT/p,p'-DDT ratios were observed, indicating mainly aged historical DDT residues in the study area.
[Show abstract][Hide abstract] ABSTRACT: Soil residual concentration of organochlorine pesticides (OCPs) were determined in 245 agricultural surface soil samples collected
from Chengdu Economic Region, Sichuan Province, Southwest China, in order to investigate their spatial distribution and the
controlling environmental factors. Results showed that detectable ratios of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane
(DDT) were very high, ranging from 88.16 (for δ-HCH) to 97.96% (for p,p′-DDE). The concentrations of DDTs were higher than HCHs, which were consistent with their historical usage in China. OCPs
concentrations in the economically developed regions (Chengdu Plain) were higher than in the less developed, mountainous region
around Chengdu Plain. The metabolite to parent ratio analysis of HCHs and DDTs indicated there were new pesticide inputs,
possibly from the use of lindane (γ-HCH) and dicofol in some regions although they have banned for agricultural use since 1983. Also, the distribution of OCP
congeners in soil was mainly governed by their individual physical and chemical characteristic, historical usage amount and
patterns, and the environmental conditions, such as, temperature, landform, soil type, etc.
Full-text · Article · Nov 2009 · Environmental Earth Sciences