Status of POPs accumulation in the Yellow River Delta: From distribution to risk assessment

Abstract

The Yellow River Delta (YRD) is a large region of China with complex pollution sources and a long history of environmental deterioration. Despite this, relatively little data exists on the status of important contaminants of concern in this region. Here, we review the literature on the status of key persistent organic pollutants (POPs) of concern including organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in the YRD. Sources, source identification methods, and spatial distribution patterns are presented. Additionally, POPs contamination levels reported in the literature were evaluated against popular regulatory limits worldwide to form a basis for overall environmental health. Our review determined that OCPs in the YRD originated mainly from current pesticide use and past agricultural pesticide application. Sources of PAHs included petrochemical inputs, coal fired plants, and wood combustion. PCB levels were impacted by the petrochemical industry as well as waste disposal of PCB containing equipment. OCPs exhibited a spatial distribution pattern that increased along the urban-rural gradient, while the opposite was seen for PAHs and PCBs. Comparisons of POPs contamination levels in the YRD with popular regulatory limits suggest that the extent of PCB contamination all mediums (sediment, soil, water, and biota) exceeded that of PAHs and OCPs. Overall pollution levels in the YRD seem to be in control; however, levels from heavily polluted point sources raise numerous concerns about the ecological health of the region and require more attention from regulatory authorities.

Organochlorine pesticides, polybrominated diphenyl ethers and polychlorinated biphenyls in surficial sediments of the Awash River Basin, Ethiopia

“…In this study the highest % proportion of HCHs was contributed by β-HCH (68.18%) followed by α-HCH (18.26%), and γ-HCH (10.97%). β-HCH is known for its high persistence and poor biodegradability in soil and sediment [ 57 – 59 ] and these properties might have contributed for its abundance in the river sediments of the Awash River Basin. [ 58 ] reported that α-HCH and γ-HCH can be biodegraded to β-HCH in the natural environment.…”

Spatial Distributions and Seasonal Changes of Current‐Use Pesticides from the North Pacific to the Arctic Oceans

“…The present study involved a large-scale investigation of the temporal and spatial distributions of CUPs in surface seawater and atmosphere. Previous studies have focused mainly on CUPs at specific regions or locations (Eickmeyer et al, 2016;Li et al, 2016;Ruggirello et al, 2010;Yeo et al, 2004), with few having largescale profiles (Ma et al, 2015). Zhong, Xie, Cai, et al (2012) studied CUPs during the 4th Chinese National Arctic Research Expedition (CHINARE) in a similar region of the North Pacific Ocean.…”

Spatial distribution and seasonal variation of four current-use pesticides (CUPs) in air and surface water of the Bohai Sea, China

“…The target compounds are expected to discharge into the Bohai Sea through the runoff of the Yellow and Haihe Rivers (Fig. 1), which are among the seven largest water systems in China, and receive large volumes of industrial or agricultural wastewater leading to serious pollution levels (Li et al, 2013;Li et al, 2016). For example, the Yellow River flows through Zibo City, which is the largest production base of Chlorpyrifos in Northern China (15,000 t/y), this may explain the high concentration of Chlorpyrifos in SW6 and SW7.…”