Persistent organic pollutants in muscle and feather of ten avian species from Māzandarān Province of Iran, on the coast of the Caspian Sea

Organochlorine pesticides and polychlorinated biphenyls in carnivorous waterbird species from Lake Ziway, Ethiopia

Abstract

This study presents the assessment of bioaccumulation and reproductive health risk associated with organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) exposure in carnivorous waterbird species. We investigated OCPs and PCBs exposure in muscle tissues of 4 species of carnivorous waterbird species from Lake Ziway, Ethiopia. The influences of trophic position and size on accumulation of organochlorine pollutants are investigated. The result shows that Dichloro-diphenyl-trichloroethanes (DDTs), Endosulfan and PCBs are detected. DDTs constitute the dominant contaminant among OCPs investigated. Trophic position and wing chord length are positively associated with levels of ∑DDTs. Mean levels of ∑DDTs and ∑PCBs vary from 143.9 to 1051.1 ng g−1 wet weight (ww) and not detected (ND)—3.5 ng g−1 ww, respectively. Mean levels of 4,4′-dichloro-diphenyl-dichloro-ethylene (p,p′-DDE), and 4,4′-dichloro-diphenyl-dichloro-ethane (p,p′-DDD) are significantly varied among the bird species. p,p′-DDE contribute 92.3–98.6% of total DDTs. About 26.7% of birds show p,p′-DDE levels above the minimum threshold to cause reproductive failures in birds. Generally, the findings of this study shows that DDT exposure in high trophic levels bird species from Lake Ziway could result in reproductive health risk. The present study may serve as a baseline for future comprehensive exposure and risk assessment studies.

Article Highlights

Organochlorine pesticides and polychlorinated biphenyls in carnivorous waterbird and fish species from Lake Hawassa, Ethiopia

Abstract

Agricultural, vector-control and industrial activities around Lake Hawassa pose a risk of organochlorine contamination of the lake biota. To assess organochlorine contamination, we measured levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in 3 species of carnivorous waterbird and 3 species of fish. A total of 50 samples of fish and bird species sampled from Lake Hawassa in 2019. We investigated factors influencing accumulation of OCPs and PCBs. Reproductive risk associated with tissue levels of 4,4’-dichloro-diphenyl-dichloro-ethylene (p,p’-DDE) is also estimated. Results show that dichloro-diphenyl-trichloroethane (DDT) is the dominant contaminant found in both bird and fish species. p,p’-DDE is the dominant DDT metabolite in both bird and fish species. Geometric mean of p,p’-DDE varied from 49.8–375.3 and 2.2–7.7 ng g−1 ww in birds and fish, respectively. Average p,p’-DDE level in birds is 33.3 times higher than in fish. p,p’-DDE constitutes 93.4–95.2% of total DDTs in bird species. Degree of exposure, chemical stability, and resistance to environmental and biological degradation could explain higher levels of p,p’-DDE both in bird and fish species. There is significant variation in p,p’-DDE levels among bird and fish species owing to differences in feeding habits, foraging habitat, and lipid content. An increase in DDT levels with increasing size is observed in both bird and fish species. A significant positive association between log-transformed p,p’-DDE, and stable nitrogen isotope ratio (δ15N) values is found. There is no reproductive health risk in bird species as a result of the current levels of p,p’-DDE.

Article Highlights

Environmental contamination and human exposure of polychlorinated biphenyls (PCBs) in China: A review

Polychlorinated biphenyls (PCBs), together with 11 other organic compounds, were initially listed as persistent organic pollutants (POPs) by the Stockholm Convention because of their potential threat to ecosystems and humans. In China, many monitoring studies have been undertaken to reveal the level of PCBs in environment since 2005 due to the introduced stricter environmental regulations. However, there are still significant gaps in understanding the overall spatial and temporal distributions of PCBs in China. This review systematically discusses the occurrence and distribution of PCBs in environmental matrices, organisms, and humans in China. Results showed that PCB contamination in northern and southern China was not significantly different, but the PCB levels in East China were commonly higher than those in West China, which might have been due to the widespread consumption of PCBs and intensive human activities in East China. Serious PCB contamination was found in e-waste disassembling areas (e.g., Taizhou of Zhejiang Province and Qingyuan and Guiyu of Guangdong Province). Higher PCB concentrations were also chronicled in megalopolises and industrial clusters. The unintentionally produced PCBs (UP-PCBs) formed during industrial thermal processes may play an increasingly significant role in PCB pollution in China. Low PCB levels were recorded in rural and underdeveloped districts, particularly in remote and high-altitude localities such as the Tibetan Plateau and the South China Sea. However, these data are limited. Human exposure to PCBs is closely related to the characteristics of environmental pollution. This review also discusses existing issues and future research prospects on PCBs in China. For instance, the accumulation characteristics and migration regularities of PCBs in food webs should be further studied. More investigations should be undertaken to assess the quantitative relationship between external and internal exposure to PCBs. For example, bioaccessibility and bioavailability studies should be supplemented to evaluate human health risks more accurately.

Application and Evaluation of Novel Chromatographic Techniques to Detect and Quantitate 108 Pesticides and Metabolites in Muscle Samples From Wild Birds of Prey

The application and evaluation of highly efficient chromatographic techniques with tandem mass spectrometry for the detection and quantitation of 108 pesticides and metabolites, some considered persistent organic pollutants, was performed in muscle samples obtained from 25 birds of prey belonging to the families Accipitridae, Falconidae, and Strigidae presented dead in 2013 to Grupo de Rehabilitación de la Fauna Autóctona y su Hábitat, in Madrid, Spain. Pesticides with prohibited use were detected at high concentrations in the muscle samples analyzed. Based on its high sensitivity to detect pesticides in muscle, the described chromatographic techniques with tandem mass spectrometry should be considered an alternative testing methodology to those commonly used for routine application in ecotoxicological forensic research.

Chlorpyrifos and persistent organic pollutants in feathers of the near threatened Olrog's Gull in southeastern Buenos Aires Province, Argentina

The use of bird feathers to assess environmental contamination has steadily increased in ecotoxicological monitoring programs over the past decade. The Olrog's Gull (Larus atlanticus) is a species endemic to the Atlantic coast of southern South America, constituting one of the three threatened gull species listed in the entire American continent. The aim of this study was to assess the exposure to Persistent Organic Pollutants (POPs) and chlorpyrifos in the Near Threatened Olrog's Gull through the analysis of body feathers sampled at the Mar Chiquita coastal lagoon, the main wintering area of the species in Argentina, controlling for sex and age class. Chlorpyrifos showed the highest concentrations among all contaminants and groups of individuals (X¯ = 263 ng g^-1), while among POPs the concentration of organochlorine pesticides was higher than polychlorinated biphenyls and polybrominated diphenyl ethers, likely indicating the current use of these agricultural contaminant in the region. The highest values of total POP concentrations (males X¯ = 280 ng g^-1, females X¯ = 301 ng g^-1) were found in juvenile gulls, likely as a consequence of the incorporation of pollutants during the breeding season. Subadult and adult birds showed difference between sexes in the concentration of contaminants, with higher levels in males than females. The results highlight the need to include birds of different sex and age classes in order to better understand the variation in pollutants loads. The present study provides relevant information to improve the conservation status of the Olrog's Gull and new insights about the environmental health of the Mar Chiquita coastal lagoon, Argentina, a MAB-UNESCO World Biosphere Reserve. However, there is a continued need for long-term monitoring programs focusing on this threatened species to understand the effects of pollutants on its population.

Non-invasive biomonitoring of organic pollutants using feather samples in feral pigeons (Columba livia domestica)

A large portion of organic pollutants (OPs) represent a potential hazard to humans and living beings due to their toxic properties. For several years, birds have been used as biomonitor species of environmental pollution. Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated biphenyl ethers (PBDEs), organophosphate pesticides (OPPs), polycyclic aromatic hydrocarbons (PAHs) and pyrethroids (PYRs) were assessed in body feather samples of 71 feral pigeons (Columba livia domestica) collected from Asturias and Galicia (NW Spain). The percentage of detection for all chemical groups were above 90% in studied birds. The general pattern was dominated by PAHs (mean value ± standard deviation (SD) 32 ± 15 ng/g) followed by OCPs (3.8 ± 1.1 ng/g), PYRs (3.4 ± 3.8 ng/g), PCBs (1.6 ± 1.0 ng/g), OPPs (1.3 ± 0.70 ng/g) and PBDEs (0.80 ± 0.30 ng/g). Significant differences were observed between age, location and gender suggesting different sources of exposure and accumulation pathways.

Assessment of persistent organic pollutants in hair samples collected from several Iranian wild cat species

Persistent organic pollutants (POPs), including the organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α, β and γ-hexachlorocyclohexane (HCH) isomers, and the polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153, and 180), were determined in hair samples collected from 41 Iranian wild cats belonging to 8 different species. This is the first report on the presence of selected POPs in feline hair from museum collections and it is an indication of the concentrations of OCPs and PCBs in Iran from 2000 to 2010. Median concentrations of HCHs, DDTs, PCBs, and HCB were 108, 99, 70 and 38 ng/g hair, respectively. p,p'-DDE and β-HCH were the most abundant OCPs (detected in 91% and 74%, respectively, of the analyzed samples), while CB 180 and CB 138 were the predominant PCB congeners, found respectively in 49% and 61% of the samples. Significant differences (p < 0.05) in the median concentrations of DDTs were found among species grouped according to both their feeding habits and territory range. Levels of DDTs and PCBs were generally higher in the omnivorous species compared with the carnivorous ones, likely due to both their dietary habits and habitat in the proximity of human settlements.

Pelagic seabirds as biomonitors of persistent organic pollutants in the Southwestern Atlantic

Persistent Organic Pollutants (POPs) are accumulated through time and can exert different effect on ecosystems. POPs and Chlorpyrifos, a current use pesticide, were assessed in body feathers of males and females of Black-browed albatross (Thalassarche melanophris, BBA) and Cape petrels (Daption capense, CAP) during their non-breeding seasons at the Patagonian Shelf, Argentina. Chlorpyrifos showed the highest values among all pollutants in both species (49.56-84.88 ng g^-1), resulting from current agricultural practices. The pattern OCPs > PCBs > PBDEs was observed in both species, and CAP showed higher concentrations than BBA probably as a consequence of higher lipid mobilization and pollutants availability during dispersion. Non-significant differences between sexes about POPs levels were found; however a slight tendency was observed, females>males in CAP, and males>females in BBA. More attention and further studies are needed to understand seabirds' physiology and its relationship with the pollutants distribution in their tissues and considering breeding season.

Persistent organic pollutants in typical lake ecosystems

Persistent organic pollutants (POPs) are highly toxic organic chemicals. Lakes are one of the main sinks of POPs. POPs can be accumulated in multiple matrices in lake ecosystems and biomagnified through the food web, and thus pose a potential threat not only to lake ecosystems, but also to human health. Given their potential persistent risks, they have received much attention over the past decades. This review comprehensively summarizes the data on the levels and distributions of POPs in selected typical lake ecosystems in China and worldwide, involving water, sediments, organisms, and surrounding soils and atmosphere. It was found that current publications on POPs in Chinese lakes are mainly related to lakes in the developed eastern plain area, with only a few studies concerning the less-developed Qinghai-Tibet Plateau area. Similarly, around the world, there are more research on POPs in developed countries and less in relatively less-developed areas. Moreover, there are significant differences in the levels of POPs in different matrices in different lake ecosystems. Legacy POPs, such as polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated diphenyl ethers (PBDEs), were commonly detected and reported in different lakes, while emerging POPs like perfluorinated compounds (PFCs), polychlorinated naphthalenes (PCNs), Tetrabromobisphenol A (TBBPA), and hexabromocyclododecane (HCBD) were relatively less detected or reported. A comprehensive summarization on the levels and distributions of traditional and emerging POPs in lake ecosystems could be significant for further understanding the behaviors and risks of POPs in lake ecosystems.

Use of feathers to assess polychlorinated biphenyl and organochlorine pesticide exposure in top predatory bird species of Pakistan

Little is known about the levels of organochlorines (OCs) in predatory bird species from Asia or the factors governing their concentrations. This study is the first report on concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in predatory birds of Pakistan. The concentrations of PCBs and OCPs were investigated using tail feathers of ten different species of predatory birds. In addition, concentration differences among body, tail, primary and secondary feathers were investigated for six individuals of black kite (Milvus migrans). Ranges of concentrations were highest for dichlorodiphenyldichloroethylene (p,p'-DDE: 0.11-2163ngg(-1) dry wt.) followed by dichlorodiphenyltrichloroethane (p,p'-DDT: 0.36-345ngg(-1) dry wt.), hexachlorobenzene (HCB: 0.02-34ngg(-1) dry wt.), ∑PCBs (0.03-16ngg(-1) dry wt.) and trans-nonachlor (TN; 0.01-0.13ngg(-1) dry wt.). CB 118, 153, 138, and 180 along with p,p'-DDE were found as the most prevalent compounds. ∑PCBs and ∑DDTs were significantly different among species (both p<0.01) and omnivorous, scavengers, carnivorous and piscivorous trophic guilds (all p<0.03). Only ∑PCBs were significantly differentamong different families of birds (p<0.01). Values of stable isotopes (δ(13)C and δ(15)N) differed significantly (all p<0.01) among species, families, trophic guilds as well as terrestrial and aquatic habitat but not between nocturnal and diurnal predators (p=0.22 for δ(13)C; p=0.50 for δ(15)N). Concentrations of ∑PCBs, ∑DDTs and trans-nonachlor, but not HCB (p=0.86), were significantly different among different feather types (all p<0.01). Trophic and taxonomic affiliation as well as dietary carbon sources (δ(13)C) for species were identified as the variables best explaining the observed variation in exposure to the studied compounds. The significance of contributing factors responsible for OC contamination differences in predatory birds should be further elucidated in future studies.

Tracking pan-continental trends in environmental contamination using sentinel raptors-what types of samples should we use?

Biomonitoring using birds of prey as sentinel species has been mooted as a way to evaluate the success of European Union directives that are designed to protect people and the environment across Europe from industrial contaminants and pesticides. No such pan-European evaluation currently exists. Coordination of such large scale monitoring would require harmonisation across multiple countries of the types of samples collected and analysed-matrices vary in the ease with which they can be collected and the information they provide. We report the first ever pan-European assessment of which raptor samples are collected across Europe and review their suitability for biomonitoring. Currently, some 182 monitoring programmes across 33 European countries collect a variety of raptor samples, and we discuss the relative merits of each for monitoring current priority and emerging compounds. Of the matrices collected, blood and liver are used most extensively for quantifying trends in recent and longer-term contaminant exposure, respectively. These matrices are potentially the most effective for pan-European biomonitoring but are not so widely and frequently collected as others. We found that failed eggs and feathers are the most widely collected samples. Because of this ubiquity, they may provide the best opportunities for widescale biomonitoring, although neither is suitable for all compounds. We advocate piloting pan-European monitoring of selected priority compounds using these matrices and developing read-across approaches to accommodate any effects that trophic pathway and species differences in accumulation may have on our ability to track environmental trends in contaminants.

A review on current knowledge and future prospects of organohalogen contaminants (OHCs) in Asian birds

The release of harmful chemicals in the Asian environment has recently increased dramatically due to rising industrial and agricultural activities. About 60% of the global human population is currently living on the Asian continent and may thus be exposed to a large range of different chemicals. Different classes of organohalogen chemicals have indeed been reported in various environmental compartments from Asia including humans and wildlife, but this issue has received less attention in birds. In this article, we reviewed the available literature on levels of legacy persistent organic pollutants (POPs) and various flame retardants (FRs) in Asian avifauna to analyze the existing pool of knowledge as well as to identify the gaps that should be addressed in future research. Furthermore, we discussed the variation in levels of organohalogens based on differences in regions, trophic level, dietary sources and migratory behaviors of species including distribution patterns in different tissues of birds. Although the mass of published literature is very low and even absent in many important regions of Asia, we deduced from the reported studies that levels of almost all classes of organohalogens (OHCs) including FRs were highest in East Asian countries such as Japan, China and South Korea, except for HCHs that were found at maximum levels in birds of South India. Concentrations (ng/g LW) of different OHCs in Asian birds ranged between <LOD (limit of detection) to 14,000,000 for polychlorinated biphenyls (PCBs), <LOD to 790,000 for dichlorodiphenyltrichloroethane (DDTs), <LOD to 12,000 for hexachlorobenzene (HCB), <LOD to 29,000 for hexachlorocyclohexanes (HCHs), <LOD to 47,000 for chlordanes (CHLs) and <LOD to 4600 for total cyclodienes. Further, ranges (ng/g LW) of 1.1 to 150,000 for Co-PCBs; <LOD to 27 for polychlorinated dibenzo-p-dioxins (PCDDs); <LOD to 45 for polychlorinated dibenzofurans (PCDFs) and 0.02 to 73 for PCDD/DFs have been reported in Asian aves. Among emerging FRs, levels of total polybrominated diphenyl ethers (PBDEs), total dechlorane plus (DPs) [syn and anti DPs] and hexabromocyclododecane (HBCDs) oscillated between <LOD to 134,000, <LOD to 3820 [<0.1-920 and <0.1-2900], and <LOD to 11,800 ng/g LW, respectively. Corresponding ranges of novel brominated flame retardants (nBFRs) such as decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) were <LOD to 820 and <LOD to 89 ng/g LW. Other nBFRs such as tetrabromobisphenol-A (TBBPA) hexabromobenzene (HBB) and pentabromoethylbenzene (PBEB) in Asian avifauna have been reported in very few studies. Dependence of organohalogens on dietary sources and subsequent biomagnification in the food chain has been corroborated through δ(15)N and δ(13)C stable isotope proxies. In general, tissues with higher fat content accumulated more organohalogens and vice versa. Aspects such as maternal transfer of OHCs and temporal trends have rarely been discussed in reported literature from Asia. The mobility of birds, vicinity to sources and trans-boundary movement of pollutants were identified as key exposure routes and subsequent OHCs contamination in Asian birds. There is extreme scarcity of literature on organohalogen contamination in birds from Northern, South-eastern and west Asian countries where an industrial boom has been witnessed in the past few decades. Current scenarios suggest that levels of OHCs, particularly the FRs, are rising in birds of Asia and it would be wise to develop baseline information and to regulate the OHCs emission accordingly.

Contaminants in the southern tip of South America: Analysis of organochlorine compounds in feathers of avian scavengers from Argentinean Patagonia

The aim of this study was to assess the exposure to organochlorine compounds (OC) in 91 primary wing feathers of avian scavengers, Turkey vulture (Cathartes aura), American black vulture (Coragyps atratus) and Southern crested caracaras (Polyborus plancus) from the southern tip of South America, in the Argentinean Patagonia. We analyzed for a series of OC including hexachlorocyclohexane (HCH) isomers, endosulfan, aldrin, dieldrin, endrin, dichlorodiphenyltrichloroethane (p,p'-DDT), dichlorodiphenyldichloroethane (p,p'-DDD), dichlorodiphenyldichloroethylene (p,p'-DDE), heptachlor and heptachlor-epoxide. This is the first study on OC in feathers of three terrestrial top carnivores from South America. OC concentrations found in the studied species were much higher than those found in feathers of raptors from Europe and Asia, which likely indicate their high use in the region, specifically in agriculture, and other possible uses of OC in this area. ∑HCH had the highest median concentration, followed by ∑Drins, ∑DDT, ∑Heptachlor, and ∑Endosulfan, similar to those reported in several food samples in Argentina. On the other hand, differences in OC profiles between species and areas may be related to feeding and migratory habits, as well as the molt period. Three individuals showed ∑DDT (DDT, DDD and DDE) concentrations in feathers related to sublethal effects. However, this comparison should be used with caution due to problems with extrapolating such data across tissues and species.

Feathers as a biomonitoring tool of polyhalogenated compounds: a review

Feathers have many advantages that make them an excellent nondestructive tool for monitoring polyhalogenated compounds (PHCs). This paper proposes a review on the PHCs in feathers and factors influencing the pollutant load. Special attention has given to external contamination and the main analytical methods used to detect these compounds in feathers. Some authors have found strong and significant correlations between the concentrations of PHCs in feathers and internal tissues, providing positive expectations for their future use in the field of ecotoxicology. However, changes in diet, time elapsed between the previous molt period and sampling, sample size, and/or external contamination have been suggested as possible causes to explain the lack of correlations reported in some studies. Further studies with newly grown feathers and blood samples would be required in order to clarify this issue. Although atmospheric deposition has been reported as cause of external contamination, preening oil seems to be the most relevant factor contributing to this process. Unfortunately, washing techniques tested to date are not able to effectively remove the surface contamination from barbs and shafts, and therefore, it is necessary to develop methods able to discriminate between internal and external contamination. Finally, in this review, deposition rate is proposed as a measurement unit, as this allows comparisons between different parts of the same feather, as well as between different feathers.