Spatial distribution and sources of organochlorine pesticides in surface waters of Shanghai, China

Abstract

The concentrations, distribution, influencing factors, and sources of 26 organochlorine pesticides (OCPs) were investigated in surface waters of Shanghai. Surface waters in this study refer to the freshwater that contains particles smaller than 0.45 μm in size. Total concentrations of OCPs ranged from 5.90 to 158.16 ng/L with a mean value of 78.11 ng/L. The OCP concentrations were generally low, but with a few relatively high concentrations at sites in the northern and southern regions of Shanghai. Dissolved oxygen, electrical conductivity, pH and oxidation-reduction potential had an important impact on the distribution of OCPs, which showed a significant negative correlation (p < 0.01). Source apportionment was carried out using isomer ratios of OCPs and Absolute Principal Component Scores-Multiple Linear Regression. Six principal components of OCPs were identified, and the contribution rates and contribution amounts were ranked: Heptachlor epoxide > HCHs > Endosufan and Methoxychlor > Propachlor > Heptachlor and DDTs > Dacthal and Chlordane. The contribution of historic residual HCHs in Shanghai's surface waters was not significantly different from that of atmospheric deposition, and a part of HCB was likely from the degradation of HCHs. DDTs were mainly from historical residues, although some were derived from recent inputs, and the main sources of heptachlors were also the historical residues. However, the recent input and historical residues of aldrins were both noticeable. The fluctuation of OCPs pollution levels and source differences among different intensive land-use types were relatively insignificant (p > 0.05).

Distribution, Sources, and Risk Assessment of Organochlorine Pesticides in Water from Beiluo River, Loess Plateau, China

“…DDTs can be degraded into DDD in an anaerobic environment and DDE in an aerobic environment [ 36 ]. The DDD/DDE ratio can be used to estimate the degradation environment of DDTs [ 37 ].…”

“…The ratio of β-HCH/(α-HCH + γ-HCH) in most of the sampling sites was greater than 0.5, indicating that HCHs in the water were mainly derived from historical residues. DDTs can be degraded into DDD in an anaerobic environment and DDE in an aerobic environment [36]. The DDD/DDE ratio can be used to estimate the degradation environment of DDTs [37].…”

“…The ratio of (DDD + DDE)/DDT can determine whether there are new DDT inputs [38]. As shown in Figure 3b, DDD/DDE and (DDD + DDE)/DDT ratios varied DDTs can be degraded into DDD in an anaerobic environment and DDE in an aerobic environment [36]. The DDD/DDE ratio can be used to estimate the degradation environment of DDTs [37].…”

Environmental factors influencing DDT–DDE spatial distribution in an agricultural drainage system determined by using machine learning techniques

“…However, DDT (and derivatives) is more frequently detected in the hydrosphere, edaphosphere, and living organisms, even in regions like European Union whose commercialization was banned decades ago (Stemmler & Lammel, 2009;Turusov et al, 2002;Villaverde et al, 2016). This fact may suggest that if an apparently not used pesticide is detectable in the environment (e.g., drainage waters in an agricultural irrigation area), a potential reservoir remains in the soil and sediments of an specific area (Albaiges et al, 1987;Chen et al, 2020;López-Flores et al, 2003;Maillard & Imfeld, 2014) that is still emerging into surface and groundwater, potentially entering into trophic chains.…”

Nontargeted Analysis Reveals a Broad Range of Bioactive Pollutants in Drinking Water by Estrogen Receptor Affinity–Mass Spectrometry

“…ERs regulate vital physiological processes in humans, such as cell growth, reproduction, development, and differentiation. − Anthropogenic chemicals can disrupt the endocrine system and adversely affect human health by activating or blocking ER signaling pathways. − Chemicals such as bisphenol A (BPA) and phytoestrogens have been reported to cause polycystic ovary syndrome , and breast cancer , and can induce neurodegeneration by mimicking 17β-estradiol (E2). , Recently, the adverse effects of several antiestrogenic chemicals on female reproductive health have raised widespread concern. For example, exposure to triphenyl phosphate (TPHP) and fluorene-9-bisphenol can delay pubertal timing, deteriorate ovarian reserve, and lead to adverse pregnancy outcomes. ,, Through target analyses, researchers have identified a growing list of ER-active chemicals in aquatic environments, such as phthalic acid esters, BPA, estrogens, , phytoestrogens, alkyl phenolics, parabens, and pesticides. , Notably, an increasing number (approximately 350,000 until 2019) of such chemicals have been registered for production and use . Because the evaluation of the estrogenic activity of most chemicals is not legally required prior to their production and use, various ER-active chemicals have been and are likely to be discharged into the environment without toxicity assessment.…”