Xinli Xing

Levels, sources and potential risks of polycyclic aromatic hydrocarbons (PAHs) in multimedia environment along the Jinjiang River mainstream to Quanzhou Bay, China.

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.

Organochlorine pesticides in soil, water and sediment along the Jinjiang River mainstream to Quanzhou Bay, southeast China

Residue levels of organochlorine pesticides (OCPs) in multiple compartments (water, soil and sediment) along the Jinjiang River mainstream to Quanzhou Bay were monitored to elucidate sources and fate. The concentrations of OCPs in surface soil of the watershed of the Jinjiang River (2.44 ± 1.97 ng/g for hexachlorocyclohexanes (HCHs) and 11.4 ± 8.46 ng/g for dichlorodiphenyltrichloroethanes (DDTs)) and the Quanzhou Bay (1.81 ± 2.15 ng/g for HCHs and 9.72 ± 14.66 ng/g for DDTs) were comparable. The concentrations of HCHs and DDTs in dissolved phase were 55-94% for the total HCHs and ten to sixteen percent for the total DDTs in the Jinjiang River. High correlations of OCPs between suspended particulate matter (SPM) and sediment (p<0.01) were found in this study, which demonstrated that OCPs absorbed onto SPM was the major source in the sediment of Quanzhou Bay. The use of lindane was the major source of HCHs in the study region. Dicofol pollution was found in water of the Jinjiang River and sediment of Quanzhou Bay. Based on the sediment quality guidelines, DDTs pose more ecotoxicological risk in environment of the Jinjiang River and Quanzhou Bay.

Organochlorine pesticides (OCPs) in soils and sediments, southeast China: A case study in Xinghua Bay

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.

Residues of Organochlorine Pesticides (OCPs) in Agricultural Soils of Zhangzhou City, China

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 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.

Concentrations and classification of HCHs and DDTs in soil from the lower reaches of the Jiulong River, China

Soil is an important source to other environmental media and organisms for organochlorine pesticides (OCPs) bioaccumulation. Twenty-four representative surface soil samples were collected from the lower reaches of the Jiulong River, China, in 2009. The concentrations of hexachlorocyclohexane isomers (HCHs) ranged from 0.38 to 39.52 ng·g−1, with a mean value of 9.51 ng·g−1. The concentrations of dichlorodiphenyltrichloroethanes (DDTs) and their metabolites were within the ranges of 0.94–700.99 ng·g−1, with a mean value of 71.17 ng·g−1. The concentrations of HCHs and DDTs in the soil were lower than the first grade level (50 ng·g−1) of the Chinese Environmental Quality Standard (GB15618-1995). Hierarchical Cluster Analysis (HCA) and Pearson’s bivariate Correlations Analysis (PCA) were used to analyse the distribution and contamination levels of OCPs in this region. The results showed that DDTs were the major contaminants and there were no significant correlations between various OCPs concentrations and the total organic carbon (TOC) contents. A significant positive correlation was observed between HCHs and DDTs (p<0.01), which indicates that HCHs and DDTs may have similar sources and fate in the study area.

Soil concentrations and soil-air exchange of organochlorine pesticides along the Aba profile, east of the Tibetan Plateau, western China

Mianzhu—Aba profile, east of the Tibetan Plateau, was selected to study the occurrence of organochlorine pesticides (OCPs) along an altitudinal gradient. Dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and Aldrin, Dieldrin and Endrin (Drins) in surface soils were detected in winter (March) and summer (July). Soil concentrations (ng·g−1, dw) in winter and summer ranged as follws: DDTs, 0.37–179.16 and 0.32–42.57; HCHs, 0.14–10.76 and 0.55–32.71; Drins, N.D-3.99 and 0.02–6.93, respectively. Main soil OCPs were p,p′-DDT, p,p′-DDE, β-HCH and Drins, among which Drins were rarely reported in current literature of the Tibetan Plateau. Higher OCP concentrations in the profile were attributed close to the agricultural fields of the Sichuan Basin, current lindane and nondicofol DDTs inputs, and also long-range atmospheric transport from abroad. Soil OCP concentrations underwent obvious seasonal variation, with higher DDTs in winter and higher HCHs and Drins in summer. It may be caused by climatic conditions, summer monsoon type, and physico-chemical properties of such contaminants. Though “rest” phenomenon occurred in some sampling sites, HCHs and Drins showed an increasing trend with increasing altitude, while DDTs showed an evident decrease with increasing altitude. The altitudinal distributions of OCPs were all consistent with previous findings in other mountainous regions. A primary fugacity analysis on OCPs soil-air exchange indicated that the profile may be secondary sources for HCHs and Endrin. As with Aldrin, Dieldrin, and DDTs, the profile may be both secondary sources and sinks.

Contamination characteristics of organochlorine pesticides in multimatrix sampling of the Hanjiang River Basin, southeast China

Hanjiang River, the second largest river in Guangdong Province, Southern China, is the primary source of drinking water for the cities of Chaozhou and Shantou. Our previous studies indicated that soils from an upstream catchment area of the Hanjiang River are moderately contaminated with organochlorine pesticides (OCPs), which can easily enter the river system via soil runoff. Therefore, OCPs, especially downstream drinking water sources, may pose harmful health and environmental risks. On the basis of this hypothesis, we measured the OCP concentrations in dissolved phase (DP), suspended particle matter (SPM), and surface sediment (SS) samples collected along the Hanjiang River Basin in Fujian and Guangdong provinces. OCP residue levels were quantified through electron capture detector gas chromatography to identify the OCP sources and deposits. The concentration ranges of OCPs in DP, SPM, and SS, respectively, were 2.11-12.04 (ng/L), 6.60-64.77 (ng/g), and 0.60-4.71 (ng/g) for hexachlorocyclohexanes (HCHs), and 2.49-4.77 (ng/L), 6.75-80.19 (ng/g), and 0.89-252.27 (ng/g) for dichloro-diphenyl-trichloroethanes (DDTs). Results revealed that DDTs represent an ecotoxicological risk to the Hanjiang River Basin, as indicated by international sediment guidelines. This study serves as a basis for the future management of OCP concentrations in the Hanjiang River Basin, and exemplifies a pattern of OCP movement (like OCP partition among multimedia) from upstream to downstream. This pattern may be observed in similar rivers in China.

Organochlorine pesticide residues in surface water from Sichuan Basin to Aba Prefecture profile, east of the Tibetan Plateau

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.

Chapter 20 – Polyurethane Foam-Based Passive Air Samplers in Monitoring Persistent Organic Pollutants: Theory and Application

Abstract This chapter reviews the principles of passive air sampler (PAS) techniques and progress of the polyurethane foam-based PAS (PUF-PAS) in monitoring persistent organic pollutants (POPs) from a local to global scale. The calibration method of the site-specific sampling rate (Rs) on the basis of the loss of depuration compounds from the PUF disk is explained, and the factors (i.e., temperature, wind speed, and atmospheric particles) that influence Rs are also discussed. A case history is presented to help explain the atmospheric transport of organochlorine pesticides from plain to mountain, as well as to demonstrate the feasibility of using PUF-PAS for achieving spatially and seasonally resolved data for POPs. And lastly, the future research prospects in the development and application of PUF-PAS is discussed.

Legacies of Organochlorine Pesticides (OCPs) in Soil of China—A Review, and Cases in Southwest and Southeast China

Abstract China has a history of intensive application and production of organochlorine pesticides (OCPs) between the 1950s and the 1980s for agricultural use and vector control. Since the early 1980s, China began to ban the agricultural use of OCPs and then signed the Stockholm Convention on persistent organic pollutants (POPs) in 2001. By 2009, most OCPs were eliminated for their production and use in China except for emergency cases. However, in recent years, residual OCPs have been detected in various environmental media, in large quantities in some areas. Therefore, this chapter briefly explains the origin and fate of OCPs in the environment and reviews the historical use of OCPs and their residual distribution in soil of China. Further, it reports case studies on the OCP distributions and some related influencing factors in the soils of the southwestern and southeastern parts of China.