Organochlorine Compounds in the Amur (Heilong) River Basin (2000-2020): A Review

Persistent organic pollutants (POPs) are well-known contaminants that raise serious concerns, even more than 20 years after they were banned. Their worldwide distribution and persistence necessitate continuous monitoring in all components of the environment. The most challenging issues of POP regulation are associated with international water resources because their solutions require international cooperation in environment protection. This review provides data on various POPs (DDT, HCH, endrin, dieldrin, and PCBs) and their concentrations in aquatic organisms inhabiting the Amur River basin, one of the most poorly explored regions of Northeast Asia. Most studies have been conducted in the Songhua River (China), a tributary of the Amur River, which indicates that large inland bodies of water, especially those of international importance, require more extensive research.

Organochlorine Pollutants in Human Breast Milk from North of the Far Eastern Region of Russia

The widespread application of pesticides in the territories of the former USSR still exerts negative impacts on their ecological status. In this regard, dedicated programs for monitoring persistent organic pollutants (POP) in humans are implemented in several countries. Our study aimed to assess the accumulation of organic pollutants in breast milk of women residing the Chukotka Autonomous Okrug (CAO). Organochlorine pesticides (OCP) and polychlorinated biphenyls (PCB) concentrations in breast milk samples were measured by gas chromatography-mass spectrometry (GC-MS). The POP concentrations in the samples varied from 13 ng/g lipid weight (lw) to 620.6 ng/g lw (median 58.3 ng/g lw). An assessment of health risk to infants fed breast milk from CAO women did not show any exceedance of the estimated daily intake (EDI). The results obtained are the indirect evidence of the presence of these compounds in the environment and their negative effects on ecosystems and human health.

Temporal trends of persistent organic pollutants biotransport by Pacific salmon in the Northwest Pacific (2008-2018)

The present study aimed to assess the biotransport of POPs, including OCPs and PCBs, by Pacific salmon (genus Oncorhynchus) on the northwestern Pacific Ocean. In 2008-2012, the Amur River basin, the eastern Kamchatka, and the mainland coast of the Sea of Okhotsk received the largest amounts of pesticides. In 2018, the transport of OCPs to the Russian northwestern Pacific reached only 1 kg, and the total OCP levels in muscles of fish from this region were significantly lower than in previous years. The average concentration of PCBs for all species under study differed from that of OCPs, with the highest concentration recorded from sockeye salmon. In 2018, pink salmon brought the largest amount of PCBs to the Russian northwestern Pacific. Coastal water pollution has decreased significantly in recent years due to the ban on the use of POPs in the Northwest Pacific (according to the measurements in 2010 and 2018).

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Pacific salmon from the Kamchatka Peninsula and Sakhalin Island, Northwest Pacific

The purpose of the present study was to determine levels of POPs (dieldrin, endrin, HCH isomers, DDT metabolites, and PCB congeners) in organs of chum (Oncorhynchus keta), pink (O. gorbuscha), sockeye (O. nerka), masu (O. masou), and Chinook salmon (O. tshawytscha), and to identify the patterns of toxicants' distribution in organisms and the environment of the northwestern Pacific. Principal component factor analysis showed that all the salmon species typically exhibit relationships between the PCB congeners and are characterized by a similar pattern of entry of PCBs 101, 118, and 153. The OCPs levels in the organs of Pacific salmon are decreasing from 2012 to 2018, which suggests the elimination of these toxicants from the northwestern Pacific Ocean.

Flounders as indicators of environmental contamination by persistent organic pollutants and health risk

The purpose of this study was to elucidate the potential of using flounders as bioindicators of accumulation and transformation of POPs and to assess the possible environmental risk to the health of the population of the Russian coastal regions. The mean levels of HCH, DDT, and PCBs in the flounders were as follows: in the eastern Sea of Okhotsk, 49 ± 51, 62 ± 89, and 106 ± 83 ng/g lipid weight; in the southern Sea of Okhotsk, 36 ± 37, 15 ± 16, and 97 ± 41 ng/g lipid wt; in the Sea of Japan/East Sea, 62 ± 36, 39 ± 28, and 1616 ± 1177 ng/g lipid wt, respectively. In the Tatar Strait, OCPs were represented mainly by β-HCH with a concentration of 221 ± 182 ng/g lipid wt; the PCB level was 455 ± 317 ng/g lipid wt. Values of ILCR = 2.1·10^-5 due to the consumption of flounder from the Sea of Japan/East Sea at a rate of 29 kg/yr indicate a probability of developing cancer during a lifetime.

Bioaccumulation of POPs in human breast milk from south of the Russian Far East and exposure risk to breastfed infants

The present study is a stage of the regular POP monitoring conducted in the framework of the Russian Federation's National Implementation Plan under the Stockholm Convention on Persistent Organic Pollutants. The POPs concentration (ΣHCH+ΣDDT+ΣPCB) in the samples ranged from 23 to 878 (with a mean of 151.4) ng/g lipid. The ranges of concentrations of OCPs (ΣHCH+ΣDDT) and PCBs were 2.8-291 and 3.2-720 ng/g lipid, respectively. The mean values of OCPs and PCBs amounted to 80.1 and 74.9 ng/g lipid, respectively. As suggested by the results of the EDI calculation, intake of PCBs is slightly high in infants. The fact that most studies have associated PCB with effects, such as development of congenital deformity, reduced immunity, lower weight, and small baby size at birth, makes it an alarming situation.

Organochlorine pesticides in commercial Pacific salmon in the Russian Far Eastern seas: Food safety and human health risk assessment

Concentration of organochlorine pesticides (OCPs) (α-, β-, γ- hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), dichlorodiphenyldichloroethylene (DDE)) in four species of Pacific salmon (pink, chum, chinook, and sockeye) are presented. OCPs in salmon organs increased in the following order: muscle < liver < eggs < male gonads. Concentrations of the OCP in salmon organs increased in following order: DDE < γ-HCH < α-HCH. The level of pollutants in salmon is compared with the sanitary and epidemiological norms of Russia and other countries. Cancer and noncancer hazard ratios through consumption of salmon in Russian Far East for both men and women also were summarized. Noncancer and cancer hazard ratio values were far below threshold values (<1.0).