Accumulation Features of Polychlorinated Biphenyls and Organochlorine Pesticides in Resident and Migratory Birds from South India

Persistent, bioaccumulative, and toxic pollutants in migratory waterbirds from Bohai Bay, China: Implications on distinct pollutant sources

Bohai Bay is an important stopover on the East Asian-Australasian flyway (EAAF) for migratory birds. In the present study, eggs of three migratory waterbird species, Little Terns (Sterna albifrons), Pied Avocets (Recurvirostra avosetta), and Black-winged Stilts (Himantopus himantopus), and local aquatic organisms from Bohai Bay (Nanpu and Dongying wetlands) were collected to determine stable isotope (13C, 15N, D) signature and concentrations of mercury (Hg), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDTs), and short-chain chlorinated paraffins (SCCPs). Organisms from Nanpu had significantly higher δD values than Dongying, which was related to local salinity. The pollution profiles showed species-specific difference in the same site, but no spatial difference for the same bird species from two wetlands. Positive correlations were observed between δ15N values and concentrations of Hg and PCBs, but not DDTs and SCCPs, because of the complex pollution sources in migration routes. The pollution exposure in the annual life cycle for Pied Avocets based on migration route information suggests that Hg and PCBs in eggs mainly originate from the breeding site (Bohai Bay), while DDTs are mainly from the wintering sites (the middle and lower reaches of the Yangtze River). Pollutants could pose considerable negative effect on eggshell thickness. The present study promotes the importance of pollutant exposure and risk assessment in the entire migration cycle for migratory birds.

Assessment of chlorinated pesticide exposure to white-rumped vulture Gyps bengalensis in India

Populations of the critically endangered white-rumped vulture (WRV) Gyps bengalensis have declined drastically due to the use of diclofenac for veterinary purposes in Indian subcontinent. Thirty-two dead WRVs collected from three states, namely Gujarat, Assam and Tamil Nadu in India between 2011 and 2014 were investigated to understand the role of diclofenac in the death, and the results were published. Furthermore, since organochlorine pesticides have been linked to long-term impact on populations in many species of birds across the globe, available tissues of 21 WRVs were tested also for six organochlorine pesticides (DDT, HCH, endosulfan, heptachlor, dieldrin and dicofol) and chlorpyrifos. All vultures were found to have had one or more detectable levels of pesticides in their tissues except one. Similarly, all the pesticides included in the study were detected in at least one of the vultures analysed. DDT (95.2%) was the most frequently detected pesticide followed by HCH (90.5%), and DDT (73.6%) contributed the most to the total pesticide load. Total pesticide load ranged between below detection limit (BDL) and 8753.4 ng/g. High levels of total pesticide load recorded in gut contents showed recent exposure to these legacy pesticides even long after their ban. However, it is perceived that studied pesticides' exposure to birds and their presence in the environment is in decreasing trend in India. Although, varying levels of pesticides were detected, all of which were below the levels reported to be toxic, and also reported earlier in the same species in India. Recorded levels may not create a problem to vultures unlike diclofenac; nevertheless, as continued exposure to the pesticides studied may lead to sub lethal effects in birds, it is prudent to monitor these pesticides along with new generation pesticides and NSAIDs in the critically endangered white-rumped vulture in India, towards its conservation.

Light pollution enhances ground-level exposure to airborne toxic chemicals for nocturnally migrating passerines

Anthropogenic activities generate different forms of environmental pollution, including artificial light at night (ALAN) and airborne toxic chemicals (ATCs). Nocturnally migrating birds are attracted to ALAN during migration and if ALAN occurs in unison with ATC, the chances of ground-level ATC contamination occurring at stopover sites could increase. Here, we document the relationship between ALAN and ATC within the contiguous United States based on 479 toxic chemicals from 15,743 releasing facilities. Using weekly diurnal estimates of relative abundance for 165 nocturnally migrating passerine (NMP) bird species, we assess how the species richness and relative abundance of NMP species are correlated with ALAN and ATC across the annual cycle. The concentration of ATC increased with increasing ALAN levels, except at the highest ALAN levels. The species richness of NMP species was positively correlated with ATC during the non-breeding season and migration, and negatively correlated during the breeding season. The relative abundance of NMP species was negatively correlated with ATC during the breeding and non-breeding seasons and the correlation did not differ from zero during migration. Through the disorienting influence of ALAN, our findings suggest large numbers of NMP species are being exposed to higher ATC concentrations at stopover sites. Outside of migration, large numbers of NMP species that winter along the US Gulf Coast are being exposed for an extended period of time to higher ATC concentrations. Initiatives designed to decrease ALAN during migration have the potential to reduce the acute and chronic effects of ATC contamination, lower the maternal transfer of toxic chemicals to eggs, and decrease the biologically mediated transport of toxic chemicals across regions. However, these initiatives will not benefit species that experience prolonged ATC exposure during the non-breeding season along the US Gulf Coast, a region that could be a significant source of ATC contamination for North American birds.

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

Widespread exposure of powerful owls to second-generation anticoagulant rodenticides in Australia spans an urban to agricultural and forest landscape

The powerful owl (Ninox strenua) is a threatened apex predator that consumes mainly arboreal marsupial prey. Low density populations reside in urban landscapes where their viability is tenuous. The catalyst for this research was the reported death of eight powerful owls around Melbourne, Australia, in less than one year (2020/2021). Eighteen deceased owls were toxicologically screened. We assessed toxic metals (Mercury Hg, Lead Pb, Cadmium Cd and Arsenic As) and anticoagulant rodenticides (ARs) in liver (n = 18 owls) and an extensive range of agricultural chemicals in muscle (n = 14). Almost all agricultural chemicals were below detection limits except for p,p-DDE, which was detected in 71% of birds at relatively low levels. Toxic metals detected in some individuals were generally at low levels. However, ARs were detected in 83.3% of powerful owls. The most common second-generation anticoagulant rodenticide (SGAR) detected was brodifacoum, which was present in every bird in which a rodenticide was detected. Brodifacoum was often present at toxic levels and in some instances at potentially lethal levels. Presence of brodifacoum was detected across the complete urban-forest/agriculture gradient, suggesting widespread exposure. Powerful owls do not scavenge but prey upon arboreal marsupials, and generally not rodents, suggesting that brodifacoum is entering the powerful owl food web via accidental or deliberate poisoning of non-target species (possums). We highlight a critical need to investigate SGARs in food webs globally, and not just in species directly targeted for poisoning or their predators.

Persistent organic pollutants and stable isotopes in the liver of Chelonia mydas stranded on the southeastern Brazilian coast

Among the various pollutants released into the environment, there are persistent organic pollutants (POPs). Chelonia mydas are one of the species that can be exposed to these pollutants and it is classified in the IUCN Red List as "endangered". The present study evaluated the occurrence of POPs in 49liver tissue samples of C. mydas juveniles collected on the southeastern Brazilian coast. Furthermore, the concentrations were correlated with carbon and nitrogen isotopic ratio, biometrics, and ecological factors. The main POPs found were ƴ-HCH and PCBs. Overall, the concentrations found were low and there were no significant correlations among POPs, isotopic ratios, size and weight, which may be related to the fact that the studied individuals are juveniles and occupy similar trophic positions despite the individual variations found. Despite the low concentrations, the presence of POPs, mainly PCBs, in the sea turtles' liver indicates their exposure to these compounds.

Contamination of habu (Protobothrops flavoviridis) in Okinawa, Japan by persistent organochlorine chemicals

Persistent organochlorine chemicals (OCs), including chlordane compounds (CHLs), DDTs, PCBs, and chlorinated dioxins and related compounds (DRCs), were examined in the adipose tissue and liver from 33 specimens of habu (Protobothrops flavoviridis), a species of venomous pit viper endemic to the Japanese Southwest Islands. The median concentrations of CHLs, DDTs, and PCBs in adipose tissue of 22 habus collected from an urban area were 4400 ng g^-1 lipid weight (lw), 610 ng g^-1 lw, and 1600 ng g^-1 lw, respectively. Their DDT and PCB concentrations were higher in comparison with the specimens from a rural area. Liver of 10 specimens from the urban area were subjected to DRCs analysis, and PCDDs, PCDFs, and DL-PCBs were detected with median values of 1300, 350, and 150,000 pg g^-1 lw, respectively. Among PCDD/F congeners, octa-CDD was detected at the highest concentrations in seven liver samples, but considerable concentrations of penta- and hexa-CDD/Fs were found in two samples. Relatively higher concentrations of PCB, DDTs, and PCDD/Fs were found in habus collected within 1 km of the boundary of military facilities, suggesting that OCs from some unknown sources of these OCs inside and/or around some of the facilities accumulated in habus.

New insights into the bioaccumulation of persistent organic pollutants in remote alpine lakes located in Himalayas, Pakistan

The current study assesses the persistent organic pollutants (POPs) in water and their bioaccumulation in Brown Trout (BT) and Rainbow Trout (RT) present in the remote alpine lakes (RALs) of Himalayas, Pakistan. Hence, these environments might receive POPs by long range atmospheric transport (LRAT) with little interferences from local anthropogenic activities. The potential transportation pathways for such accumulation can be atmospheric precipitation, melting ice and glacial runoff. The results indicated that the sum of mean concentrations of organochlorine pesticides (OCPs (DDTs + HCHs)) in water of Glacial-fed lakes, Ice melting-fed lake and Rain-fed lake ranged from 0.21 to 317, 0.14-293, 0.16-235 pg L-1, respectively, while those of polychlorinated biphenyls (PCBs) are 0.275-16.02, 0-15.88, 0.234-14.46 pg L-1, respectively. Similarly, the sum of mean concentrations of all investigated PCBs and OCPs in BT ranged from 0.008 to 0.715 ng g-1 and 0.003-3.835 ng g-1 based on wet weight (ww), while for RT these concentrations were 0.002-0.557 ng g-1 and 0.001-1.402 ng g-1 (ww), respectively in the selected RALs. The PCBs and OCPs levels in both water and fish tissues were observed in order of Glacial-fed lakes > Ice melting-fed lake > Rain-fed lake. The results proposed that melting of ice and glacial water are more significant sources of the contaminants (PCBs and OCPs) in the freshwaters of RALs of Himalayas as compared to rainfall water. The positive correlation between water contamination and the selected fish species confirmed that these can be used as a bio-indicator for future research studies. However, the impact of POPs as they cascade through downstream ecosystems remains largely unexplored. The additional study of contaminant dynamics should be extended to a wide range of mountain environments of Himalayas, where melt-water used for drinking and irrigation purposes by billions of people reside alone the waterways that originated from these remote areas.

Organochlorine pesticides in feathers of three raptor species in southern Brazil

In this study, we determined the presence of organochlorine pesticides (OCPs) in back feathers from three raptor species, Phalcoboenus chimango, Milvago chimachima and Caracara plancus. Samples were obtained from live animals and ten OCPs were detected: α-HCH, β-HCH and γ-HCH (lindane), heptachlor, heptachlor epoxide, aldrin, endosulfan I, endosulfan II, endosulfan sulfate and p,p'-DDE. The concentrations found were higher than those reported in other raptor species, and C. plancus showed greater values than P. chimango and M. chimachima for all the substances. These differences may be justified by the species feeding habits and the characteristics of the sampling area, since C. plancus were sampled in an area with a higher concentration of agricultural crops and urbanized environments. In relation to the possible negative effects, four individuals of C. plancus presented DDE values related to sublethal effects for other species. This is the first study reporting OCPs in back feathers of these species in Brazil, and further studies evaluating OCP exposure and related effects are important for a better understanding of the consequences of different OCP concentrations on the health of these species.

Effects of migration and reproduction on the variation in persistent organic pollutant levels in Kentish Plovers from Cangzhou Wetland, China

Migratory Birds have been considered biovectors of persistent organic pollutants (POPs) from sources to remote areas. In the present study, Kentish Plovers (Charadrius alexandrines) were collected in different periods, including immigration, breeding and emigration, to investigate the effects of migration and reproduction on POP variations in this bird species. Significant differences were found for dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB) concentrations in muscles between the immigration and emigration periods (p < 0.01 and p < 0.001, respectively), which could be attributed to the higher pesticide residues in the wintering grounds of plovers. Female plovers could excrete about 20.8-42.7% of POP load into eggs. Nevertheless, the POP levels didn't exhibit great reduction during the breeding period compared with other seasons, which suggested that the breeding status had little impact on POP levels in female plovers. The estimated mean transport masses of POPs driven by plover migration were at the milligram level (range: 0.02-7.05 mg), suggesting that the migration of plovers had limited impacts on the redistributions of POPs along their migratory routes.

Is current information on organochlorine exposure sufficient to conserve birds in India?

Organochlorine compounds (OCs) pose a serious threat towards the wildlife due to their well-known adverse effects. India is the second largest producer of pesticides in Asia, with DDT production still ongoing, and is ranked amongst the leading countries of pesticide consumption. However, a significant data gap in avian biomonitoring studies has been identified in Asia. The objective of this review is to compile and discuss the available literature on concentrations of organochlorine pesticides and PCBs in Indian birds. The review of 18 articles showed that DDTs were the OCs most frequently analysed, followed by HCHs and PCBs (highest hepatic mean values: 11.6, 1.8 and 1.03 µg/g ww, respectively). The most frequently analysed matrix was whole body homogenates, followed by internal tissues. Plasma, eggs, feathers and guano were poorly sampled. The range of sampling years was 1980-2007. In general, hepatic OC concentrations were below the level known to cause adverse effects, although p,p'-DDE in eggs was found in concentrations associated with eggshell thinning. Most of the studies were carried out in Southern India (Tamil Nadu). Out of 106 species studied, house crow (Corvus splendens) was the most frequently monitored. However, the number of individuals sampled per species is generally low and different sample types are used, thus, huge limitations to compare OC exposure exist. This review shows that there is a clear deficit of data on OC concentrations and sublethal effects that needs to be addressed to understand the status of OC exposure, spatio-temporal trends and potential impacts in Indian avifauna.

Incidences of mortality of Indian peafowl Pavo cristatus due to pesticide poisoning in India and accumulation pattern of chlorinated pesticides in tissues of the same species collected from Ahmedabad and Coimbatore

Incidences of mortality of Indian peafowl Pavo cristatus, the national bird (Schedule I Indian Wild Life Protection Act 1972), are rampant in India. Between January 2011 and March 2017, around 550 peafowl in 35 incidences were reported dead across the country. Due to the non-availability of fresh carcases, poisoning could not be confirmed. Birds which died due to kite string injuries in Ahmedabad (15) and accidents in Coimbatore (5) were tested for residues of chlorinated pesticides, namely hexachlorocyclohexane (HCH), dichloro-diphenyl-trichloroethane (DDT), endosulfan, heptachlor, dicofol, dieldrin and cholipyrifos. The liver, kidney and muscle were the tissues considered to document pesticide load. Total load ranged from BDL to 388.2 ng/g. DDT (95%) and HCH (80%) were detected more frequently. DDT (40%) and endosulfan (26%) contributed maximum to the total pesticide load followed by HCH (21%). Pesticide accumulation pattern among the organs was in the order of liver (123.9 ng/g) > kidney (91.9 ng/g) > muscle (19.5 ng/g) with significant difference (p < 0.05). Peafowl from Ahmedabad had significantly (p < 0.05) higher level of total pesticide (149.0 ng/g) than birds from Coimbatore (47.8 ng/g). Although varying levels of chlorinated pesticide were detected, they were below reported toxic limits. Nevertheless, persistence of chlorinated pesticides and poisoning due to modern pesticides across the entire distribution range of Peafowl in India is a cause for concern.

Persistent organic pollutants in red-crowned cranes (Grus japonensis) from Hokkaido, Japan

The red-crowned crane (Grus japonensis) from eastern Hokkaido is classified as a Special Natural Monument in Japan. In this study, we determined the concentrations of persistent organic pollutants (POPs) in red-crowned crane muscle tissues (n = 47). Polychlorinated biphenyls (PCBs) had the highest median concentration (240ng/g lipid weight), followed by dichlorodiphenyltrichloroethane and its metabolites (DDTs) (150ng/g lipid weight), chlordane-related compounds (CHLs) (36ng/g lipid weight), hexachlorobenzene (HCB) (16ng/g lipid weight), hexachlorocyclohexanes (HCHs) (4.4ng/g lipid weight), polybrominated diphenyl ethers (PBDEs) (1.8ng/g lipid weight), and finally, Mirex (1.5ng/g lipid weight). Additionally, a positive correlation was found among POP concentrations. No sex differences beyond body parameters were observed. Additionally, red-crowned cranes exhibited a high enantiomeric excess of (+)-alpha-HCH, with enantiomer fractions varying from 0.51 to 0.87 (average: 0.69).

Organohalogenated contaminants in plasma and eggs of rockhopper penguins: Does vitellogenin affect maternal transfer?

Although many studies have investigated organohalogenated contaminants (OHCs) in yolk, little is known about the mechanisms and timing of transfer of OHCs from the female to the egg. Vitellogenin, a yolk precursor, has been suggested to play a role in this transport. We here report for the first time the temporal changes in OHC and an index of vitellogenin concentrations in female plasma from the pre-laying period to clutch completion in free-living birds: the southern rockhopper penguin (Eudyptes chrysocome chrysocome) breeding in the Falkland/Malvinas Islands. In addition, OHC concentrations in the corresponding clutches were analysed. OHC concentrations in female plasma and in the yolk of both the first (A-) and the second (B-)eggs followed a similar pattern, with hexachlorobenzene (HCB) > Σpolychlorinated biphenyls (PCBs) > Σdichlorodiphenyltrichloroethanes (DDTs) > Σmethoxylated polybrominated diphenyl ethers (MeO-PBDEs) > Σchlordanes (CHLs) > Σpolybrominated diphenyl ethers (PBDEs) ≈ Σhexachlorocyclohexanes (HCHs). The higher concentrations of MeO-PBDEs compared to PBDEs indicate a diet containing naturally-produced MeO-PBDEs. All OHC compounds except for PBDEs increased from the pre-laying period to A-egg laying and subsequently declined from A-egg laying to B-egg laying, and female plasma vitellogenin showed the same pattern. For ΣPCBs and ΣMeO-PBDEs, we found positive correlations between female plasma during A-egg laying and both eggs, and for HCB between female plasma and A-eggs only. During pre-laying, only ΣMeO-PBDEs correlated between both eggs and female plasma, and no correlations between OHC concentrations in eggs and female plasma were found during B-egg laying, highlighting that maternal transfer of OHCs is time- and compound-specific. Finally, female vitellogenin concentrations did not significantly correlate with any OHC compounds in either female plasma or eggs, and our results therefore did not confirm the suggested role of vitellogenin in the maternal transfer of OHC molecules into their eggs.

DDTs and other organochlorine pesticides in tissues of four bird species from the Rift Valley region, Ethiopia

Despite the presence of a wide variety and number of birds, there is exceedingly little data on organochlorine pesticide (OCP) residues in birds inhabiting in Africa. In the present study, concentrations of dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes, drins, cyclodienes, and hexachlorobenzene were measured in liver, kidney, heart and brain of 4 bird species from the Rift Valley region, Ethiopia. Indoor residual spraying of DDT for malaria vector control, and indiscriminate and illegal use of pesticides underline the relevance of this study. Levels of ΣOCPs ranged from 1.87 to 4586ng/g wet weight, and the scavenger bird species Leptoptilos crumeniferus had the highest level in liver. In all tissues, contamination profiles of OCPs within the species were similar, with DDTs≫other OCPs. Among the DDTs, p,p'-DDE was the most abundant compound and had significantly a higher burden in all tissues. The risk characterization demonstrated potential risks to the studied birds associated with DDE exposure. Maximum hepatic levels of p,p'-DDE exceeded the levels reported to trigger adverse effects. The detection of p,p'-DDT in all bird tissues suggests the release of fresh DDT to the environment. This is the first study to assay OCPs in different tissues of birds from the Ethiopian Rift Valley region, and henceforth the data will serve as a reference data for future studies.

Seasonal Differences in Contaminant Accumulation in Neotropical Migrant and Resident Songbirds

For many years, it has been hypothesized that Neotropical migrants breeding in the United States and Canada accumulate organochlorine pesticides (OCPs) while on their wintering grounds in Latin America. We investigated the seasonal accumulation of persistent organic pollutant (POPs) in migrant and resident passerines in Texas, Yucatán, and Costa Rica collected during the fall, winter, and spring from 2011 to 2013. A total of 153 birds were collected, and all contained detectable levels of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and OCPs with dichlorodiphenyldichloroethylene (DDE) being the most predominant pesticide. OCPs and PCBs were the predominant contaminants, accounting for ≥80 % of the total POPs burden, whereas PBDEs accounted for ≤16 %. Only spring migrants from Texas had significantly greater DDE concentrations (64.6 ng/g dry weight [dw]) than migrants collected in Costa Rica (23.2 ng/g dw). Resident birds in Texas had significantly greater levels of DDE (121 ng/g dw) and ΣPBDEs (34.8 ng/g dw) compared with residents in Yucatán and Costa Rica. For ΣPCBs, resident birds from Costa Rica had significantly lower concentrations (9.60 ng/g dw) compared with their migrant counterparts (43.7 ng/g dw) and residents from Texas (48.3 ng/g dw) and the Yucatán (32.1 ng/g dw). Migrant and resident passerines had similar congener profiles for PCBs and PBDEs suggesting similar exposure and retention of these contaminants. No significant accumulation of DDE was observed in migrants while on their wintering grounds. Relatively high concentrations of PBDEs in resident birds from Costa Rica warrant future studies of PBDE contamination in Latin America.

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.

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.

Recent status of organohalogens, heavy metals and PAHs pollution in specific locations in India

Our group of scientists at the Center for Marine Environmental Studies (CMES), Ehime University, Japan has been carrying-out studies in India from the 1980s on chemicals contamination. Due to its agrarian economy, use of fossil fuels, industries, growing population and urbanization, chemicals such as pesticides, dioxins and related chemicals (DRCs), brominated flame retardants (BFRs), heavy metals, and polyaromatic hydrocarbons (PAHs) are widely spread in India. We have published a review (Subramanian and Tanabe, 2007) covering papers published until 2005, on India. A decade had passed and this is the time to provide an update of the spatial and temporal changes during this period and hence this review. At many instances organochlorines such as DDTs and HCHs showed decreasing trends even though they are still at considerable levels. Novel chemicals such as PCDDs/Fs are seen at municipal solid waste dumping sites of India at levels equivalent to similar locations of the developed world. In the e-waste processing sites in India, especially the informal ones, apart from PCDDs/Fs, some brominated flame retardants (BFRs) and heavy metals were present as contaminants. Metro cities of India showed location specific contamination by HCHs, DDTs, PCDDs/Fs, BFRs, PAHs, etc. Coastal regions of India seem to be still unpolluted when compared to the nearby inland locations. This review is concerned mainly with the chemicals that we (CMES) have been evaluating in India in the past three decades. We suggest the importance of further studies, future directions for policy decisions and also for implementing control measures.

Contaminants of legacy and emerging concern in terrestrial passerines from a nature reserve in South China: Residue levels and inter-species differences in the accumulation

Knowledge is limited about the bioaccumulation of persistent halogenated compounds (PHCs) in terrestrial wildlife. Several PHCs, including dichlorodiphenyltrichloroethane (DDT) and its metabolites (designated as DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenylethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), and stable isotopes (δ(15)N and δ(13)C) were analyzed in the muscle of four terrestrial passerines, Parus major, Copsychus saularis, Pycnonotus sinensis and Pycnonotus jocosus, from a nature reserve in South China. P. major had the highest PHC concentrations, with median values of 1060, 401, 92, 25 and 0.3 ng/g lipid weight for DDTs, PCBs, PBDEs, DBDPE and BTBPE, respectively. Fractions of DDT in P. jocosus and PCBs 153, 118 and 180 in C. saularis were higher compared with the other species. The inter-species differences in PHC concentrations and profiles could be attributed to the differences in trophic level, diet, living habits and metabolic capacity among the birds.

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.

Chlorinated pollutants in blood of White stork nestlings (Ciconia ciconia) in different colonies in Spain

The aim of this study was to investigate the levels of persistent chlorinated pollutants (POPs) in wild birds. The concentrations of multiple POPs, including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in plasma of White stork nestlings. Blood samples were collected from three breeding colonies located in the West of Spain that were exposed to different environmental conditions and human activities. The concentrations of PCBs were below the limit of detection in all samples. The OCPs Heptaclor, 4,4′-DDE, endosulfan and aldrin were detected most frequently in plasma from White stork nestlings. From these four compounds, 4,4′-DDE and Heptaclor were found in high abundance. OCPs could not be detected in the colony breading nearby a landfill and an intensive agricultural area, indicating that these banned compounds are not taken up by crops growing in this area. However, birds from the colony breading next to a landfill exhibited the highest OCPs levels. These high levels might be due to exposure of the mothers to OCPs during their migration to Africa and subsequent transfer to their eggs.

Organochlorine pesticides in bird species and their prey (fish) from the Ethiopian Rift Valley region, Ethiopia

Organochlorine pesticides (OCPs) and stable isotopes were measured in muscle from 4 bird and 5 fish species from the Ethiopian Rift Valley region where DDT is used for malaria control and vast agricultural activities are carried out. We investigated the bioaccumulation of OCPs such as DDTs, HCHs, chlordanes, and heptachlors between the species, and examined the potential risk posed by these compounds for bird species. Significant differences in contaminant profiles and levels were observed within the species. Levels of total OCPs ranged from 3.7 to 148.7 μg/g lipid in bird and 0.04 to 10.9 μg/g lipid in fish species. DDTs were the predominant contaminant, and a positive relationship between δ(15)N and ΣDDT concentrations was found. The main DDT metabolite, p,p'-DDE was the most abundant and significantly greater concentrations in bird species (up to 138.5 μg/g lipid), which could have deleterious effects on survival and/or reproduction of birds.

Cattle egrets as a biosentinels of persistent organic pollutants exposure

We investigated selected chlorinated pollutants (β-HCH, γ-HCH, DDDs, DDEs, o,p'-DDT, p,p'-DDT, heptachlor, aldrin, dieldrin, and endrin) in the Lahore and the Sialkot districts of Pakistan, using eggs of cattle egret (Bubulcus ibis) collected during May and June 2007. The pollutant with highest level and frequency was ΣDDT, followed by β-HCH, γ-HCH, heptachlor, aldrin, dieldrin, and endrin in descending order. The concentration(s) were significantly higher in Sialkot heronry for all the pollutants (except p,p'-DDT) than in Lahore. The values for DDTs, β-HCH, γ-HCH, and heptachlor were significantly higher (p < 0.05) in the egg(s) than in sediment(s) and in the chicks' diet, due to biomagnification. Among DDTs analogues, p,p'-DDD was the major contaminant with >60 % of total DDT burden, reflecting the widespread aged as well as recent use of DDT as well as anaerobic degradation (DDD/DDE > 1 in many cases) in the nearby paddy soils. In few samples, p,p'-DDT/(DDD + DDE) > 0.5 suggested the recent emission patterns from surrounding contaminated areas of demolished DDT units and obsolete pesticide stores. The higher levels of HCHs (i.e., β-HCH) in the samples collected from Sialkot indicate exposure from long-term agricultural use. Overall, concentrations of all studied POPs were less than the threshold levels known to affect reproduction. Nevertheless, total DDTs and/or HCHs burdens in some eggs contained concentrations of greater than what would educe adverse effects on birds. This is among few studies on OCPs exposure to avian species, which provide the evidence of Pakistan's contribution toward the Global POPs emission.

Levels of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and organochlorine pesticides in various tissues of white-backed vulture in India

This study provides information on the current status of contamination by polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) in the tissues of endangered White-backed Vulture Gyps bengalensis in India. Chemical analyses revealed detectable amounts of PAHs, PCBs, and OCPs. Concentration ranges of ∑PAHs, ∑PCBs, and ∑OCPs in tissues were 60–2037 ng/g, 30–5790 ng/g, and 3.2–5836 ng/g wet weight, respectively. 1,1-Dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p′-DDE) concentrations ranged from below detectable level to 599 ng/g wet weight, representing more than 90% of the total dichlorodiphenyltrichloroethane (DDT). Among the various OCPs analyzed, p,p′-DDE was detected most frequently. All the contaminants recorded show higher accumulation in liver than other tissues. Levels of contaminants measured in the tissues of vulture are comparable with the levels documented in a number of avian species and are lower than those reported to have caused deleterious effects. Although no threat is expected from the current level of contamination, the presence of varying levels of contaminants and their additive or synergistic toxicity is a cause of concern to vultures. Values reported in this study can serve as guideline for future research.

Using the kingfisher (Alcedo atthis) as a bioindicator of PCBs and PBDEs in the dinghushan biosphere reserve, China

The Dinghushan Biosphere Reserve is a nature reserve and a site for the study of tropical and subtropical forest ecosystems. Rapid industrialization and intensive electronic waste-recycling activities around the biosphere reserve have resulted in elevated levels of industrial organic contaminants in the local environment that may cause adverse effects on wildlife that inhabits this area. In the present study, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and 2 alternative brominated flame retardants (BFRs)-decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE)-were investigated in the biosphere reserve and a reference site by using the kingfisher (Alcedo atthis) as a bioindicator. Residue concentrations in kingfishers from the Dinghushan Biosphere Reserve ranged from 490 ng/g to 3000 ng/g, 51 ng/g to 420 ng/g, 0.44 ng/g to 90 ng/g, and 0.04 ng/g to 0.87 ng/g lipid weight for ∑PCBs, ∑PBDEs, DBDPE, and BTBPE, respectively. With the exception of the BTBPE, these levels were 2 to 5 times higher than those detected in kingfishers from the reference site. The contaminant patterns from the biosphere reserve were also different, with larger PCB contributions in comparison with the reference site. The estimated predator-prey biomagnification factors (BMFs) showed that most of the PCB and PBDE congeners and BTBPE were biomagnified in kingfishers from the biosphere reserve. The calculated toxic equivalent quantity (TEQ) concentrations of major coplanar PCB congeners in kingfishers from the biosphere reserve ranged from 18 pg/g to 66 pg/g wet weight, with some of these TEQ concentrations reaching or exceeding the levels known to impair bird reproduction and survival.

Uptake of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) by river water fish: the case of River Chenab

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in eleven edible fish species (5 herbivorous and 6 carnivorous) collected from the River Chenab, Pakistan, during 2007-2009. Total OCP and PCB concentrations (ng g(-1) wet weight, ww) ranged between 13-107 (mean: 38) and 3.1-93.7 (mean: 20) for five herbivorous fish species and 21.6-365 (mean: 148) and 2.5-108 (mean: 30) for six carnivorous species, respectively. The trends of detected organochlorine pesticides (OCPs) in fish samples were: DDTs>PCBs>chlordanes>HCHs. The mean concentration(s) (ng g(-1) ww) of OCPs were relatively higher in all fish species collected near industrial areas followed by urban and agricultural areas. Risk assessment of OCPs and PCBs indicated that fish intake may pose health risk to humans with a consumption rate of >8 g/person/day. The hazardous ratios for the 50th and 95th percentile data of OCPs and PCBs in fish exceeded the value of 1, suggesting that the daily exposure to OCPs and PCBs yield a lifetime cancer risk greater than 1 in 10,000.

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.

Individual variation in body burden, lipid status, and reproductive investment is related to maternal transfer of a brominated diphenyl ether (BDE-99) to eggs in the zebra finch

Avian eggs are exposed to hydrophobic contaminants through maternal transfer. How maternal transfer of contaminants within a species is influenced by individual variation in characteristics such as body burden, yolk precursor levels, or reproductive investment is not understood. The authors investigated sources of variation in the maternal transfer of 2,2',4,4',5-pentabromodiphenyl ether (BDE-99) in zebra finches (Taeniopygia guttata). The authors dosed adult female zebra finches with levels of BDE-99 relevant to exposure in wild birds (0, 33.7 or 173.8 ng/g body wt/d) for three weeks prior to pairing. Maternal BDE-99 and very-low-density lipoprotein (VLDL) in plasma were measured during egg formation and at clutch completion, and BDE-99 was measured in the corresponding egg. The lipid-normalized egg-to-maternal tissue BDE-99 relationship decreased with increasing maternal burden. Individual variation in maternal VLDL was related to BDE-99 transfer to the eggs when BDE-99 was at background levels in control birds, but not when BDE-99 was elevated in dosed birds. The decrease in maternal plasma BDE-99 over the laying period was only significant (p < 0.05) in the high-dose birds. Finally, the decrease in BDE-99 in maternal plasma during egg-laying was significantly positively correlated with clutch mass in the high-dose group. These results suggest that the relationship between maternal and egg contaminant levels can be highly variable. This has significant implications for using eggs as indicators of adult or environmental concentrations.

Organochlorine pesticides and polychlorinated biphenyls in common buzzard (Buteo buteo) from Sicily (Italy)

In the present study, we investigated the concentrations and distribution of organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs) in intestine, liver, and muscle samples of 11 common buzzards (Buteo buteo) from Sicily used as bioindicator for monitoring pollution in environment. All samples of common buzzards were collected at the "Recovery Center of Wild Fauna" of Palermo, through the Zooprophilactic Institute. Quantitative determination of OCs and PCBs in the samples examined has been carried out using HRGC-ECD and GC-MS. The results obtained show the presence of concentrations of ∑DDT and ∑PCB in almost all samples. Regarding ∑DDT (4,4(')-DDE, 2,4(')-DDD, 4,4(')-DDD, 2,4(')-DDT, and 4,4(')-DDT), the highest concentrations were found in intestine (0.411 ± 0.050 μg/g) followed by muscle (0.130 ± 0.017 μg/g) and liver samples (0.109 ± 0.014 μg/g). As regards the ∑PCB congeners (PCB-28, PCB-52, PCB-95, PCB-99, PCB-101, PCB-110, PCB-138, PCB-146, PCB-149, PCB-151, PCB-153, PCB-170, PCB-177, PCB-180, PCB-183, and PCB-187), the highest concentrations were found in intestine (1.686 ± 0.144 μg/g) followed by liver (1.064 ± 0.162 μg/g) and muscle samples (0.797 ± 0.078 μg/g). Our data deserve particular attention not only for their significance but especially because they were recorded in Sicily, a region with a very low risk of environmental pollution due to the shortage of industries.

Contamination levels and spatial distribution of organochlorine pesticides in soils from India

Organochlorine pesticides, dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), are potential chemical pollutants extensively used for agriculture and vector control purposes due to low cost and high effectiveness. Concentrations of HCH and DDT were determined in 175 surface soil samples from different agricultural fields, fallow and urban lands of districts Nagaon and Dibrugarh, Assam, India. The mean concentrations of total HCH and total DDT were 825 ng/g (range: 98-1945 ng/g) and 903 ng/g (range: 166-2288 ng/g) in district Nagaon while 705 ng/g (range: 178-1701 ng/g) and 757 ng/g (range: 75-2296 ng/g) in district Dibrugarh, respectively. The soils from paddy fields contained highest amounts of HCH and DDT residues. Total organic carbon was found to be positively associated with soil HCH and DDT residues. Ratios of DDT/(DDD+DDE) were 1.25 and 1.82 while of α/γ HCH were 2.78 and 2.51 for districts Dibrugarh and Nagaon, respectively. Source identification revealed that soil residue levels have originated from long past and recent mixed source of technical HCH and Lindane for HCHs and mainly technical DDT for DDTs. Spatial distribution was also investigated to identify the areas with higher pesticide loadings in soil.

Razorbill (Alca torda) feathers as an alternative tool for evaluating exposure to organochlorine pesticides

The aim of this study was to explore the usefulness of feathers as a biomonitoring tool for organochlorine pesticides (OC) in a razorbill population (Alca torda). Fifteen OC were analyzed in feathers, including α-, β- and δ-hexachlorocyclohexane, lindane, aldrin, dieldrin, endrin, endosulfan I and II, endosulfan sulfate, p,p'-DDT, DDD, DDE, heptachlor and its epoxide. The geometric mean concentrations observed in this study were ∑DDT 67.40 ng/g, ∑HCH 62.88 ng/g, ∑Heptachlor 61.75 ng/g, ∑Endosulfan 19.70 ng/g, and ∑Drins 10.17 ng/g. The higher OC levels found in this study compared with other studies are probably affected by the razorbill diet and migration status. However, levels found in the feathers of the present study are related to concentrations in internal tissues below those which cause adverse reproductive and behavioral effects or other signs of organochlorine-pesticide poisoning in birds. Age does affect the concentration of OC pesticides in feathers. Thus, feathers would appear to be a promising tool for OC biomonitoring in seabirds, since it is possible to quantify OC compounds.

Induction of apoptosis in mussel Mytilus galloprovincialis gills by model cytotoxic agents

Apoptosis signaling pathway was investigated in the marine mussel Mytilus galloprovincialis exposed to various stressors. Analyses were performed in mussels exposed to two major pollutants of the aquatic environment: tributyltin and the water soluble fraction of diesel oil, for 1 h and animals were then maintained in sea water for a recovery period of 6 and 24 h. Apoptosis was evaluated at several levels of the cell signaling cascade by measuring Bcl-xS expression, caspase-3 activity and DNA damage (Fast micromethod(®) and TUNEL techniques). H(2)O(2) was used as a control of apoptosis induction for validation of the assays. Results showed an induction of Bcl-xS expression, a protein implicated in apoptosis, after 1 h exposure to all concentrations of chemicals. Moreover, in the same manner, apoptotic DNA damage was induced with all chemicals tested. Besides, caspase 3 activity was detected after 1 h exposure to low doses of TBT and diesel oil while the high concentrations induced this protein after 6 h. The achieved data were also correlated with our previous study, demonstrating an induction of the mitogen-activated protein kinase (MAPK) activity in the mussel M. galloprovincialis exposed to the same conditions. In conclusion, this study was one of the first characterizing the MAP kinase cell signaling pathway leading to apoptosis in the mussel M. galloprovincialis exposed to chemicals. It showed for the first time that the Bcl-xS protein was present in these mussels as in other species and played a role in apoptosis mediation. Moreover, the main originality of this work was that it showed that two apoptotic pathways might be present in the mussel: a caspase 3-dependent and a caspase 3-independent pathways.

Assessment of organochlorine pesticides in human milk and risk exposure to infants from North-East India

Despite the worldwide ban on use of persistent organochlorine pesticides, their usage continued until recently in India, for vector-borne disease eradication programs and agricultural purposes. The concentrations of organochlorine contaminants, DDT and HCH, have been determined in human breast milk from Dibrugarh and Nagaon districts of Assam state, North-East India. The results demonstrated that the mean levels of total DDT were 3210 ng/g lipid wt. and 2870 ng/g lipid wt. and total HCH were 2720 ng/g lipid wt. and 2330 ng/g lipid wt. in Nagaon and Dibrugarh respectively. There was no significant difference in the levels of investigated pollutants between the two districts. Significant differences in ADI (Average daily intake) for total DDT were found between the two districts. In addition, a positive correlation was observed between OCP levels in breast milk and age of mothers. Based on OCP levels in human breast milk, the ADI by the infants has been estimated. It has been found that high daily intake of DDTs and HCHs by the infants exceeded the TDI (Tolerable daily intake) which implied that infants of the region are potentially at high risk by these contaminants.

Polychlorinated biphenyls and organochlorinated pesticides in birds from a contaminated region in South China: association with trophic level, tissue distribution and risk assessment

PURPOSE

Birds have been used successfully for biomonitoring of the levels and effects of persistent organic pollutants (POPs) in the environments; however, there is exceedingly little data on organochlorinated pesticide (OCPs) and polychlorinated biphenyls (PCBs) residues in bird inhabiting in China. In the present study, we detected the concentrations of PCBs, dichlorodiphenyltrichloroethane and its metabolites (DDTs) and hexachlorocyclohexanes (HCHs) in muscle, liver and kidney of birds that inhabit in an e-waste recycling site. Associated with the stable isotope ratio (δ (15)N), we investigated the effect of trophic level on the body burdens of persistent contaminants in birds. The tissue distributions of contaminants in these birds were examined, and a preliminary risk assessment was also conducted.

MATERIALS AND METHODS

Specimens from eight bird species were collected from Qingyuan County, Guangdong Province, South China. Pectoral muscle, liver and kidney tissues were Soxhlet-extracted and finally dissolved in isooctane. Both PCBs and OCPs were analyzed by gas chromatography-mass spectrometry. The subsamples for nitrogen stable isotope analysis were lyophilized, ground and analyzed by a flash EA 112 series elemental analyzer interfaced with an isotope ration mass spectrometer.

RESULTS AND DISCUSSION

PCBs exhibited the highest concentrations among all target compounds, and a preliminary risk assessment suggested that adverse effects might occur in some birds for its high level. Generally, the concentrations of pollutants in liver and kidney were higher than those in muscle, which was mainly driven by passive diffusion to the 'lipid-compartment'. Significant differences in level of contaminants were obtained among species due to the varieties in dietary composition and habitat. An increasing trend was obtained between concentrations of PCBs and DDTs with trophic levels; however, HCHs exhibited the same level among species.

RECOMMENDATIONS AND PERSPECTIVES

Because of the e-waste recycling activities, the study area has been heavily polluted by PCBs. Studies on the species-specific hazard assessment associated with exposure to PCBs are urgently needed in the study of birds in the area.

Assessing seasonal and spatial trends of persistent organic pollutants (POPs) in Indian agricultural regions using PUF disk passive air samplers

The first survey of persistent organic pollutant (POP) concentrations in air across several Indian agricultural regions was conducted in 2006-2007. Passive samplers comprising polyurethane foam (PUF) disks were deployed on a quarterly basis at seven stations in agricultural regions, one urban site and one background site. The project was conducted as a sub-project of the Global Atmospheric Passive Sampling (GAPS) Network. In addition to revealing new information on air concentrations of several organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), the study has demonstrated the feasibility of conducting regional-scale monitoring for POPs in India using PUF disk samplers. The following analytes were detected with relatively high concentrations in air (mean for 2006 and 2007, pg/m(3)): α- and γ-hexachlorocyclohexane (HCH) (292 and 812, respectively); endosulfan I and II (2770 and 902, respectively); p,p'-DDE and p,p'-DDT (247 and 931, respectively); and for the sum of 48 PCBs, 12,100 (including a site with extremely high air concentrations in 2007) and 972 (when excluding data for this site).

Organochlorine residual concentrations in cattle egret from the Punjab Province, Pakistan

In this study, residual concentration of organochlorine pesticides (OCPs) in the sediments, prey, and eggs of Bubulcus ibis were measured from three breeding heronries from the Punjab province of Pakistan. Pattern of contamination in eggs followed the order: DDTs>HCHs>heptachlor>aldrin. Overall, pesticide residual concentrations were greater in eggs of cattle egrets collected from heronry on the River Ravi. Among HCHs, γ-HCH was more prevalent in eggs, whereas DDTs followed the order: DDD>DDE>p,p'-DDT>o,p'-DDT. Eggshell thinning was detected which showed negative relationship with residual concentration of DDE. In prey samples, residual concentration of POPs followed the order: DDTs>HCHs>dicofol>heptachlor; however, contamination pattern in sediments followed a slightly different order: DDTs>heptachlor>dicofol>HCHs>dieldrin>aldrin. Concentration of β-HCH was more prevalent in sediments and comparatively greater concentrations of POPs were measured in sediments collected from the River Ravi. Dicofol was found for the very first time in the biological samples from Pakistan, and its concentration was measured as relatively high in eggs from heronry from the River Chenab. Residual concentrations measured in eggs were below the levels that could affect egret populations. Biomagnification of the total OCPs through the food chain was evident in three breeding heronries. The concentration of DDE measured in eggs of the cattle egret suggests the need for monitoring this contaminant in other bird species at different trophic levels.

Organochlorines and mercury in livers of great cormorants (Phalacrocorax carbo sinensis) wintering in northeastern Mediterranean wetlands in relation to area, bird age, and gender

Wild birds are exposed to pollutants in their habitats. Top consumers of aquatic environments such as the fish-eating great cormorant (Phalacrocorax carbo sinensis) are especially affected due to the bioaccumulation of toxic substances in their tissues. This study analysed the livers of 80 great cormorants from Greece to estimate the concentration of organochlorines and mercury and to examine their possible toxic effects and origin. The results showed that mercury (geometric mean 8089 ng g⁻¹ dw), p,p'-DDE (2628 ng g⁻¹ dw), ∑HCHs (47 ng g⁻¹ dw) and HCB (116 ng g⁻¹ dw) concentrations can be considered high compared with those found in great cormorant livers elsewhere except in highly polluted areas, whereas ∑PCBs occurred in relatively low concentrations (1091 ng g⁻¹ dw). β-HCH was the dominant HCH isomer. Pollutant levels were generally unrelated to area, age and gender. However, p,p'-DDE and p,p'-DDD showed intersite differences, whilst the proportion of PCBs with 8 chlorine atoms were significantly higher in adult than 1st year great cormorants. Pollution did not reflect local patterns but rather these along the Baltic and Black Seas, whilst differences in p,p'-DDE concentration and ∑DDTs/∑PCBs ratios between Evros, Axios or Amvrakikos, found on common migration route, suggested different bird origins. Most birds had toxic mercury concentrations; 83.7% above 4000 ng g⁻¹ dw and 16% above 17,000 ng g⁻¹ dw. Other pollutant levels were too low to have adverse effects.

Assessment of organochlorine pesticide exposure in a wintering population of razorbills (Alca torda) from the southwestern Mediterranean

Sixteen organochlorine pesticides (OC) were analyzed in several tissue types (abdominal and subcutaneous fat, liver and brain) from juvenile (n=14), immature (n=9), subadult (n=7) and adult (n=20) razorbill (Alca torda) collected from the southwestern Mediterranean coastline, in the East of Spain (La Marina, Elche, Alicante, Spain). These razorbills had drowned in fishing nets (most probably) while searching for food. The objective was to assess the exposure to organochlorine pesticide residues in this wintering population of marine birds. This paper presents, as far as we are aware, the first published data on OC concentrations in razorbills. The highest levels were found in abdominal fat followed by subcutaneous fat, liver and brain. A significant positive relationship was found between age and OC levels in tissues, and with the highest levels in adults. The group of sigma Drins had the highest concentrations, followed by sigma DDT, sigma Endosulfan, sigma HCH and sigma Heptachlor, with endrin aldehyde being the compound which reached the highest levels. The p,p'-DDE/p,p'-DDT ratio in fatty tissues suggests exposure to non-degraded DDT and thus is present in the environment despite its prohibition. The OC levels detected were higher than those found in other studies on Alcidae, which may be explained by the Mediterranean habitat in which the birds were found. However, these levels are below concentrations for which any observable effect has been described.

Activation of MAP kinase signaling pathway in the mussel Mytilus galloprovincialis as biomarker of environmental pollution

Stimulation of MAP kinase signal transduction pathway by various stressful stimuli was investigated in the marine bivalve Mytilus galloprovincialis. Analyses were performed in animals exposed in laboratory to selected pollutants and in mussels collected in winter and summer along the eastern Adriatic coast (Croatia). Effects of oxidative stress, induced by tributyltin, hydrogen peroxide and water soluble fraction of diesel fuel on the activation/phosphorylation of the three Mitogen-Activated Protein Kinases (MAPKs) p38, JNK and ERK using a newly developed ELISA procedure were evaluated. MAP kinase activation was analyzed 1h after exposure of mussels to chemical agents, and after recovery periods of 6 and 24h. Our results clearly indicated that pollutants generated different patterns of induction of the MAPK phosphorylation. Indeed, only pp38 and pJNK were activated with 11, 33 and 100 microg/L TBT, reaching a maximum activation after 6h in seawater following treatment of mussels with 11 microg/L TBT. Treatment with 0.074 and 0.222 mM H2O2 enhanced activation of both p38 and ERK. These two kinases were activated after 1h exposure, followed by a diminution after 6h of recovery in seawater and a reactivation after 24h. The levels of phosphorylated P38 and JNK were increased after mussel exposure with 7.5, 15 and 30% of water soluble fraction of diesel oil. P38 was activated concentration dependently at 1h exposure. Additionally, field study pointed out seasonal differences in MAP kinases activation as mussels collected during summer had a higher enzyme activation state than in winter, as well as sampling site differences which could be correlated to the industrial/tourism activity and environmental stresses (salinity). All the results converge towards MAP kinase signaling pathway being induced by various pollutants in M. galloprovincialis. This signaling cascade should be considered as a possible biomarker of environmental stress and pollution.

Organochlorine pesticide and polychlorinated biphenyl in feathers of resident and migratory birds of South-west iran

Persistent organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), alpha-, beta-, and gamma-hexachlorocyclohexane (HCH) isomers, together with polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153, and 180) were determined in tail feathers from 35 birds belonging to 15 species, all originating from the southwest of Iran (Khuzestan, coast of the Persian Gulf) and kept in museum collections. The patterns of organochlorine contaminants (OCs) in birds varied depending on their migratory behavior. Resident birds contained higher median PCB concentrations (<LOQ-151 ng/g feather) than HCHs, DDTs, and HCB. Locally migrating birds had higher median concentrations of HCHs (19-83 ng/g feather). In contrast, long-distance migrants had lower concentrations of HCB and HCHs. A positive correlation was observed among OCs in these birds, suggesting that trophic level, feeding strategy, and taxonomic group are influencing factors for the OC concentrations in bird feathers. An estimate of the risk associated suggests that levels of OCPs and PCBs were lower or close to the threshold reported to affect reproduction in 1990s.

Organochlorine pesticide and polychlorinated biphenyl residues in feathers of birds from different trophic levels of South-West Iran

Persistent organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), alpha, beta and gamma-hexachlorocyclohexane (HCH) isomers, together with polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153 and 180), were determined in tail feathers from 37 birds belonging to 18 species, all originating from the South-West of Iran (Khuzestan, coast of the Persian Gulf). This is the first report on organochlorine contaminants in feathers from museum collections and it is an indication of the concentrations of OCPs and PCBs in the past (1991-1996). Median concentrations of HCHs, DDTs, PCBs and HCB were 22, 14, 11 and 10 ng/g feather, respectively. Significant correlations (p<0.05) were calculated between OCPs (except HCB) and PCBs in the bird feathers. p,p'-DDE and gamma-HCH were the most abundant OCPs, while CB 180, CB 138 and CB 101 were the predominant PCB congeners in almost all species. Significant differences (p<0.05) in the mean concentrations of DDTs and PCBs were detected among species grouped according to their feeding habits. Levels of DDTs and PCBs were highest in the carnivorous species and lowest in the herbivorous species. Levels of OCPs and PCBs in feathers of bids in the 1990s were generally below the thresholds reported to affect reproduction.

Polybrominated diphenyl ethers (PBDEs) in free-range domestic fowl from an e-waste recycling site in South China: levels, profile and human dietary exposure

To evaluate the status of polybrominated diphenyl ethers (PBDEs) contamination in poultry and sequentially human exposure through consumption of poultry in an e-waste recycling site in South China, two kinds of free-range domestic birds, chicken and duck, were collected and their muscle and liver tissues were analyzed for 16 PBDE congeners. Chicken shows higher PBDE concentrations (summation of 16 PBDE congeners) in both muscle and liver tissues, ranged from 5.7 to 4381 and from 1.5 to 7897 ng/g (lipid weight, the same hereinafter), respectively, compared to duck, ranged from 2.4 to 51 and from 1.9 to 134 ng/g. Different living habitat and feeding habits between the two species might be responsible for this observation. No sex-related differences in PBDE concentrations were found for the two species, while the PBDE concentrations in muscle were higher than those in liver for chicken. The PBDE concentrations in muscle of chicken in the present study were higher than the levels of PBDEs in chicken from other studies reported by far. BDE209 and nona-BDEs were the major congeners in poultry. Comparison of PBDE profiles between birds and environmental matrix implied that the biodebromination of BDE209 might occur in poultry. The intake of PBDEs through consumption of poultry ranges from 7.8 ng/day to 3582 ng/day with a medial 68 ng/day, which is comparable to the calculated values through consumption of all foodstuffs in other studies. The present study suggested that the total dietary PBDEs intake for local residents might be considerably enhanced due to the e-waste recycling activity.

Persistent organochlorines in human breast milk from major metropolitan cities in India

The present study was carried out to understand the current contamination status of organochlorine compounds (OCs) in human breast milk from three metropolitan cities in India (New Delhi, Mumbai and Kolkata). Among the OCs analyzed, DDTs were predominant followed by HCHs and PCBs. CHLs and HCB levels were much lower. Contamination patterns were different in human milk found in our previous study in Chennai, a metropolitan city in southern India, indicating region specific exposure routes and variable sources. In comparison with previous data, levels of DDTs and HCHs generally declined with time, implying the effect of various bans and restrictions on their usage. No association between concentrations of OCs and demographic characteristics such as parity and age of mothers was observed which might be due to narrow range of mother's age. Estimated daily intake shows that some infants are exposed to OCs to a greater extent, particularly HCHs than the guideline standard.

Organochlorine residue levels in livers of birds of prey from Spain: inter-species comparison in relation with diet and migratory patterns

Livers from 130 specimens corresponding to 18 species of raptors from Spain were analysed for persistent organochlorine (OC) residues. In all species, p,p'-DDE was the most abundant individual OC compound detected, with geometric means ranging from 61 to 40,086 ng/g ww. The geometric mean for summation operator PCB ranged from 225 to 9184 ng/g ww. Migration to Africa, south of Sahara, where p,p'-DDT is still in use, was not associated with higher liver concentrations of its metabolite, p,p'-DDE. The presence of birds in the diet of the species was an important species-specific factor determining the mean liver concentrations of p,p'-DDE and summation operator PCB. The effect of the diet on OC concentrations in liver is explained by the lower metabolising capacity of OC compounds in birds, especially for p,p'-DDE.