Organochlorine Contaminants Research Articles

Assessment of organochlorine pesticide contamination in waterbirds from an agricultural region, Central China.

Twenty-one organochlorine pesticides (OCPs) were measured in the muscle of six predominant waterbird species from Jianghan Plain, Hubei Province, Central China. Among OCPs, DDTs were the most prevalent compounds, with average concentration ranging from 31.1 to 1445ng/g lipid weight. Little egrets (Egretta garzetta) and Chinese pond herons (Ardeola bacchus) showed significantly higher concentrations of OCPs (p<0.05) due to their dietary habits and migratory patterns. There were no statistically significant differences (p>0.05) for most OCPs between sex and age groups. The accumulation profiles of HCHs and DDTs suggested that these OCPs in Jianghan Plain were largely derived from historical usage. Risk assessment indicated that heptachlor could be likely to pose adverse health effects on people consuming ducks in Jianghan Plain.

A Systematic Review of Organochlorinated Pesticide Residues in Caspian Sea Fishes

Context: The worldwide production and application of pesticides, especially organochlorine in agriculture can have adverse environmental pollution and human health risks. Thus, this review evaluated and summarized the toxicological data on the existence and concentrations of organochlorine compounds in Caspian sea fish tissues. Evidence Acquisition: The data were collected from published articles in PubMed, ISI, SID, Google Scholar and so on. Results: The review showed that nine studies were recorded in databases about pesticide residues in Caspian sea fish tissues. These studies reported that there is limited evidence of organochlorinated compounds in Caspian sea fishes. All researchers detected organochlorine contaminants in examined fishes in the studied area, however DDTs was the predominant pesticides. Heptachlor, Polychlorinated Biphenyls (PCBs) and Linden were ranked next, respectively. Conclusions: In conclusion, toxicological studies showed that, although contamination level in Caspian sea fishes was relatively low, the present status might pose a risk about food chain contamination.

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 (δ13C and δ15N) 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 δ13C; p=0.50 for δ15N). 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 (δ13C) 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.

Organochlorine contaminants in the muscle, liver and brain of seabirds (Larus) from the coastal area of the Southern Baltic

The presence of persistent organic pollutants in the environment manifests itself most strongly in the marine trophic chain, where the highest link is comprised of seabirds. At the same time, seabirds are excellent indicators of contamination in their habitat. The present study concentrates on toxic substances: polychlorinated dibenzo-p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFs) and chlorinated organic pesticides (OCPs) accumulated in the livers, pectoral muscles and brains of dead gulls collected along the Polish coast of the Baltic Sea in the years 2010–12. The highest toxic equivalence was determined in the livers of Larus argentatus (TEQ(birds TEF)−28.3pgg−1 ww) and Larus marinus (TEQ(birds TEF)−29.9pgg−1 ww.). However, the toxic equivalence of muscles was lower and amounted to 3.9pgg−1 ww. and 7.8pgg−1 ww. respectively for the two species. The lowest toxic equivalence was found in the brains of birds, where only one, the most toxic, 2,3,7,8 TCDD congener was found (TEQ(birds TEF) 0.87pgg−1 ww). The highest concentration of chloroorganic pesticides was determined in the brains of the birds (total OCP 167.8pgg−1 ww.), lower concentrations were found in the livers (total OCP 92.1pgg−1 ww.) and muscles (total OCP 43.1pgg−1 ww.). With regard to pesticides, the highest proportion in the total OCP content was constituted by DDT and its isomers (liver 81%, muscles 77% and brain 55%).High concentrations of the studied pollutants in the livers of gulls found dead on the coast of the Southern Baltic could have been effected by levels of contamination in the birds’ last meals, which resulted in a seven-fold increase of the liver’s toxic equivalence and a two-fold increase in OCP concentration in relation to muscles.

Bioaccumulation of organochlorine pesticides and polychlorinated biphenyls by loaches living in rice paddy fields of Northeast China

The concentrations of 21 organochlorine pesticide (OCP) residues and 18 polychlorinated biphenyl (PCB) congeners were measured in two loach species (Misgurnus mohoity and Paramisgurnus dabryanus) and the soils of their inhabiting rice paddies from three typical rice production bases of Northeast China to explore the main factors influencing the bioaccumulation. The concentrations of ∑18PCBs and ∑21OCPs in loaches were determined to be in the ranges of 0.14–0.76 ng g−1 wet weight (ww) and 1.19–78.53 ng g−1 ww, respectively. Most of loaches showed the considerably high contamination levels of dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), which accounted for over 97% of the total OCPs. The much lower maximum allowable loach consumption rates (<15 g d−1) indicated a high carcinogenic risk that results from the consumption of rice-field loaches. The field biota-soil accumulation factor (BSAF) was calculated as a main measure of bioaccumulation potential. The comparisons of BSAF values and the results of multivariate analysis indicated that habitat-specific environmental conditions, mainly the paddy soil contamination levels and average temperature, decisively affected the bioaccumulation of organochlorine contaminants. When the influence of lipid contents was offset, M. mohoity loaches were found to have a higher potential to accumulation PCBs and OCPs than P. dabryanus loaches, while the bioaccumulation potentials did not exhibit significant differences between juvenile and adult loaches and between male and female loaches. The octanol-water partition coefficient (KOW) was the main chemical factor influencing bioaccumulation potentials. The BSAF values presented an increasing tendency with increasing log KOW values from 6.0 to approximately 7.0, followed by a decreasing tendency with a continuous increase in log KOW values. Moreover, loaches exhibited an isomeric-selective bioaccumulation for p,p′-chlorinated DDTs, α-HCH, β-HCH, δ-HCH and cis-chlordane.

The status of organochlorine pesticide contamination in the soils of the Campanian Plain, southern Italy, and correlations with soil properties and cancer risk

The distribution, inventory, and potential risk of organochlorine pesticides (OCPs), including Hexachlorocyclohexanes (HCHs) and Dichlorodiphenyltrichloroethanes (DDTs), and their correlation with soil properties and anthropogenic factors were investigated in soils of the Campanian Plain. The total concentrations of HCHs and DDTs ranged from 0.03 to 17.3 ng/g (geometric mean: GM = 0.05 ng/g), and 0.08–1231 ng/g (GM = 14.4 ng/g), respectively. In general, the concentration of OCPs in farmland and orchards was higher than on land used for non-agricultural purposes. There are significant differences in the concentration of OCPs in the soils across the region, more specifically, the Acerra-Marigliano conurbation (AMC) and Sarno River Basin (SRB) are recognized as severely OCP-contaminated areas. The recent application of technical HCHs and DDTs in large quantities appears unlikely in light of the ratio of α-HCH/β-HCH and p,p′-DDT/p,p′-DDE, and the prohibition of the use of these chemicals in Italy nearly forty years ago. The clear correlation between the concentration of DDTs and organic carbon suggests a typical secondary distribution pattern. The mass inventory of OCPs in soils of the Campanian Plain is estimated to have a GM of 17.3 metric tons. There is no clear evidence linking the impact of geographical distribution of OCPs on the incidence of cancer, and the 95% confidence interval of total incremental lifetime cancer risk (TILCR) data falls below the internationally accepted benchmark value of 1 × 10−5.

Organochlorine Contaminants, Immunocompetence and Vitellogenin in Herring Gulls (Larus argentatus) and Great Black-Backed Gulls (Larus marinus) Nesting on Lake Ontario in 2001–2002

Abstract. In 2001–2002, Great Black-backed Gull (Larus marinus) eggs from Lake Ontario had significantly higher concentrations of organochlorine contaminants than Herring Gull (L. argentatus) eggs. This study investigated whether higher contaminants in Great Black-backed Gulls affected immunocompetence, packed cell volume (PCV) and body condition in chicks, endocrine disruption and body condition in adults, and reproductive success. Variables were compared between species at two Lake Ontario sites (one in Ontario, Canada, and one in New York, USA), and with a control site in the Bay of Fundy, Canada. For Herring Gull chicks, body condition and total antibody titers to sheep red blood cells were greater at one contaminated site; PCV, phytohemagglutinin-P stimulation and reproductive output did not differ among sites. For Great Black-backed Gull chicks, PCV was significantly lower at one contaminated site; there were no other significant differences among sites. Between species, Herring Gull chicks had sign...

Bioaccumulation of organochlorine contaminants in fish species from Lake Qarun, a protected area of Egypt

ABSTRACTThe purpose of this study was to determine concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in Nile tilapia (Oreochromis niloticus) and Bouri fish (Mugil cephalus) from Lake Qarun, a protected area of Egypt, and evaluate the relative ecological risk of these compounds. Different tissues of the fish species were analyzed for 26 chlorinated pesticides and 29 PCB congeners. Total concentrations (µg/kg wet weight, ww) of OCPs ranged between 1487 and 6217 (mean: 3260) and of PCBs between 9.0 and 61 (mean: 34). The trend of detected organochlorine pollutants was: endrin aldehyde > dieldrin > hexachlorobenzene > PCBs > endrin > 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethanes (DDTs). Heptachlor epoxide; oxy-, cis-, and trans-chlordane; trans-nonachlor; β-hexachlorocyclohexane; δ-hexachlorocyclohexane; and endosulfan I and endosulfan sulfate levels were below the detection limit. The ratios of (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylenes [DDEs] + 1,1-dichloro-2,2-bis(p-chlorophenyl)ethanes [DDDs])/ΣDDTs in fish tissues indicated no recent DDT exposure. Concentrations of DDTs and PCBs were generally comparable or higher than those found in studies of similar species worldwide. The concentrations of hexachlorobenzene, dieldrin, and endrin aldehyde in fish muscles exceeded the maximum residue level recommended by various organizations.

Identification and level of organochlorine insecticide contamination in groundwater and iridology analysis for people in Upper Citarum cascade

Organochlorines are the main pollutants in the class of persistent organic pollutants which are types of pollutants that are being questioned worldwide due to chronic persistence, toxicity and bioaccumulation. Human around the Citarum River are still using groundwater as a drinking source. It is very risky for people health that consume groundwater because in 2009 the application of organochlorine still found in the Upper Citarum watershed rice field and had potential to contaminate groundwater. Groundwater was analyzed with nine species belonging to the organochlorine pollutants Organic Peristent types. 7 types of organochlorinesAldrin was detected with an average concentration of 0.09 ppb, dieldrin with an average concentration of 24 ppb, heptaklor with an average concentration of 0.51 ppb, with concentrations of endosulfan on average 0.73 ppb, DDT with average concentration of 0.13 ppb, Lindan with an average concentration of 1.2 ppb, endrin with an average concentration of 0.03 ppb. Types with the highest concentration of organochlorine a lindan and endosulfan. Residues of aldrin, dieldrin and heptaklor in groundwater already exceeds the quality standards for drinking water Permenkes 492/2010. Based on the iridology analysis obtained several systems are expected to nervous, immune and reproductive system disorders and toxin deposits under the skin.

A Review of Organochlorine Contaminants in Nearshore Marine Mammal Predators

Nearshore vertebrate predators such as marine mammals and otters are apex predators, and as such, act both as drivers of the ecosystems in which they live and as sentinels of environmental health. As apex predators, these wild animals at the top of the food chain often bioaccumalate persistent organic pollutants (termed POPs) widespread throughout the environment. Organochlorines are a type of POP that tends to be lipophilic and hydrophobic which accumulate in the fatty tissues of marine mammals and other vertebrate predators over time. There has been growing concern about these POPs in the marine environment and within wildlife, as they can potentially cause health problems. Since the 1950s there have been 81,000 papers published on organochlorines in nearshore predators and potential negative effects to the environment, wildlife and humans. Here, we review organochlorines reported in the tissues of marine mammals and other nearshore vertebrate predators since 1995. We focus on five organochlorines that have been studied the most within nearshore vertebrate predators: 2,2-bis-(p-chlorophenyl)-1,1,1-trichloroethane or dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), toxaphene, and polychlorinated naphthalnese (PCNs).

Organochlorine contaminant concentrations in multiple tissues of free-ranging Steller sea lions (Eumetopias jubatus) in Alaska

The relationships of selected organochlorine (OC) contaminants between blubber, blood, feces, and milk of young, free-ranging Steller sea lions (Eumetopias jubatus) were examined. Both between and within each tissue there was considerable individual variation. In spite of the variation, similar patterns were observed across the tissues for most of the selected PCB congeners. In all four tissues, the major PCB congeners were PCB101, PCB118, PCB138, and PCB153. The most prominent congener, both as a weight (ng/g lipid) and as a percentage of summed PCBs (∑PCBs), was PCB 153. Comparisons between paired tissues showed that ∑DDTs in blubber samples were related to concentrations in blood, feces, and milk. The ∑PCBs in blubber were related to concentrations in milk and fecal samples, though the relationship with feces was weak. Our findings show milk samples, in particular, are useful for assessing OCs in young sea lions. Blubber concentrations of PCB101, PCB118, and PCB138 were an order of magnitude higher than those in milk, supporting the biomagnification of these PCB congeners in SSL tissues. The findings indicate alternative tissues may be used as indicators of relative contaminant exposure in lieu of surgical blubber biopsy.

Polychlorinated biphenyls and organochlorine pesticides in atmospheric particulate matter of Northern China: distribution, sources, and risk assessment

The objectives of this work are to track the contamination levels, distribution characteristics, and sources of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in atmospheric particulate matter (APM) of Northern China and to provide more comprehensive and fundamental data for risk assessment of organochlorine contaminants (OCs) in environments. Samples were extracted and purified by the microwave-assisted extraction and solid-phase extraction system, respectively. PCBs and OCPs were analyzed by gas chromatograph-mass spectrometer. The concentrations of ΣPCBs and ΣOCPs ranged from 0.73 to 112.65 ng/g and 0.14 to 34.73 ng/g, respectively. PCBs in atmospheric particulates collected from Shijiazhuang City had the highest concentration, whereas OCP congeners were at the relatively low levels. However, the highest concentration of OCPs occurred in Yongning City. The principal component analysis indicated that the predominant compositions of PCBs in most of samples were tetrachlorobiphenyl (Tetra-CB), pentachlorobiphenyl (Penta-CB), hexachlorobiphenyl (Hexa-CB), and heptachlorbiphenyl (Hepta-CB), while hexachlorocyclohexanes (HCHs), DDTs, chlordanes, and endosulfans were the dominant components of OCPs, which was attributed to their application characteristics. OCs in those particles were further used to assess a potential cancer risk to humans via ingestion, dermal contact, and inhalation. Cancer risk was evaluated in airborne particles caused by PCBs and OCPs. TEQPCBs values suggested that the representative areas were subject to different pollution degrees. However, the pollution of OCPs in certain areas should be a concern due to 41.6% of the high risk, which could pose a potential risk to organisms.

Historical trends of organochlorine pesticides in a sediment core from the Gulf of Batabanó, Cuba

Sediments can be natural archives to reconstruct the history of pollutant inputs into coastal areas. This is important to improve management strategies and evaluate the success of pollution control measurements. In this work, the vertical distribution of organochlorine pesticides (DDTs, Lindane, HCB, Heptachlor, Aldrin and Mirex) was determined in a sediment core collected from the Gulf of Batabanó, Cuba, which was dated by using the 210Pb dating method and validated with the 239,240Pu fallout peak. Results showed significant changes in sediment accumulation during the last 40years: recent mass accumulation rates (0.321gcm−2yr−1) double those estimated before 1970 (0.15gcm−2yr−1). This change matches closely land use change in the region (intense deforestation and regulation of the Colon River in the late 1970s). Among pesticides, only DDTs isomers, Lindane and HCB were detected, and ranged from 0.029 to 0.374ngg−1 dw for DDTs, from<0.006 to 0.05ngg−1dw for Lindane and from<0.04 to 0.134ngg−1 dw for HCB. Heptachlor, Aldrin and Mirex were below the detection limits (∼0.003ngg−1), indicating that these compounds had a limited application in the Coloma watershed. Pesticide contamination was evident since the 1970s. DDTs and HCB records showed that management strategies, namely the banning the use of organochlorine contaminants, led to a concentration decline. However, Lindane, which was restricted in 1990, can still be found in the watershed. According to NOAA guidelines, pesticides concentrations encountered in these sediments are low and probably not having an adverse effect on sediment dwelling organisms.

Organochlorine contaminants (PCBs, DDTs, HCB &amp; HBDE) in fish from the Lake Varna and Lake Beloslav, Bulgaria

Abstract Concentrations of organochlorine compounds such as polychlorinated biphenyls (PCBs), DDT and its metabolites, hexachlorobenzene (HCB) and hexachlorobutadiene (HBDE) were determined in three fish species: goby (Neogobius melanostomus), golden grey mullet (Mugil auratus) and silverside (Atherina boyeri). Samples were collected from the Lake Varna and the Lake Beloslav in 2014. The edible fish tissues were analyzed in order to investigate the presence of pollutants in species from the lakes near Varna City, Bulgaria and compared the results to the levels in other aquatic ecosystems. The fifteen congeners of PCBs, HCB, HCBD, DDT and its two main metabolites DDE and DDD were determined by capillary gas chromatography system with mass spectrometry detection. The OCPs levels in the wild fish were found in the order DDTs &gt; PCBs. The other contaminants HCB and HCBD were not detected or were below the analytical detection limit. Among the pesticides, essentially only the metabolites p, p’- DDE and p, p’- DDD were found. The concentrations of DDTs were determined from 2.66 to 17.97 ng/g wet weight and PCBs concentrations were found from 0.43 to 8.05 ng/g ww (in goby and golden grey mullet, respectively). The sum of the six Indicator PCBs did not exceed the European maximum limit 75 ng/g wet weight. The concentrations of DDTs and PCBs were found lower compared to those in similar fish species from other aquatic ecosystems.

Organochlorine contaminants and maternal offloading in the lecithotrophic Pacific angel shark (Squatina californica) collected from southern California

Pacific angel sharks (Squatina californica) are a benthic elasmobranch that occupy intermediate trophic level positions in coastal food webs. Angel sharks’ life history characteristics make them susceptible to accumulating high amounts of contaminants. Four angel sharks were opportunistically captured in southern California and their liver and uterine contents were analyzed for PCBs, DDTs and other pesticides. High DDT:PCB ratios were found in the sharks indicating direct or indirect foraging near a local EPA Superfund Site. Organic contaminants were measured in ovulated eggs, indicating that females are able to maternally offload contaminants. Despite the potential mismatch between ovarian and uterine fecundity, we estimated females to offload approximately 13±5% of their total body load, which represents the upper limit of this capability. Although low in sample size, the initial findings from this study suggest that habitat use might play an important role in contaminant accumulation in this species.

Accumulation of organochlorines in the European clam (Ruditapes decussatus) and sediment of the Oualidia lagoon (Morocco).

This study focused on the analysis of organochlorine pesticides and PCBs in tissue samples of the clam, Ruditapes decussatus, in the Oualidia lagoon. Tissue assays were conducted during February to December 2005 and sediment (October 2005) was also tested. 13 organochlorine compounds and eight PCBs congeners were investigated, is HCB, γ-HCH, chlordane, cis-chlordane and trans-nonachlor, DDT and its metabolites DDD, DDE, heptachlor, its epoxide, mirex and PCBs (PCB28 + 50, PCB52, PCB101, PCB 118, PCB138, PCB153, PCB180). Analysis of these compounds was performed using a gas chromatography capillary column and an electron capture detector. Organochlorine contamination of clams and sediments in the lagoon did not exceed tolerable thresholds according to European standards. The levels of tPCB, tDDT and tOCP in clams are high at 49.4, 22.2, and 7.1 ng g(-1) dw respectively. Concentrations of trans nonachlor and mirex are low compared to other chlorinated pesticides. PCB28 + 50, PCB52 and PCB101 show typical values in sediment, at 18.5, 10.8 and 17.8 ng g(-1) dw respectively.

Humpback Dolphins: A Brief Introduction to the Genus Sousa.

The delphinid genus Sousa has recently undergone a major revision, and currently contains four species, the Atlantic humpback (Sousa teuszii), Indian Ocean humpback (Sousa plumbea), Indo-Pacific humpback (Sousa chinensis), and Australian humpback (Sousa sahulensis) dolphins. Recent molecular evidence suggests that humpback dolphins in the Bay of Bengal may comprise a fifth species. These moderate-sized dolphin species are found in shallow (<30m), coastal waters of the eastern Atlantic, Indian, and western Pacific oceans. Abundance and trends have only been studied in a few areas, mostly in eastern Africa, China, and northern Australia. No global, empirically derived abundance estimates exist for any of the four species, but none appear to number more than about 20,000 individuals. Humpback dolphins feed mostly on small fishes, and sometimes shrimps; occur for the most part in small groups (mostly 12 or less); have limited nearshore movements; and in most parts of their range exhibit a fission/fusion type of social organization. Major threats that affect all the species are entanglement in fishing gear, and habitat degradation/destruction from various forms of coastal development. Impacts from vessel traffic (including behavioural disturbance and displacement, as well as mortality and morbidity from collisions with vessels) appear to be significant in most areas. Several other threats are apparently significant only in particular parts of the range of some species (e.g. high levels of organochlorine contaminants affecting Indo-Pacific humpback dolphins in Hong Kong). Direct hunting only occurs in limited areas and primarily on a small scale. Conservation actions so far have been limited, with most populations receiving little study and almost no management attention. Much more work is needed on humpback dolphin population status, threats, and how the major threats can be reduced or eliminated. Extinction risks for the four species and some populations are preliminarily re-assessed using the IUCN Red List criteria in the current volume. The results suggest that all four species in the genus are threatened at some level (suggested Red List status ranges from Vulnerable for S. chinensis and S. sahulensis to Critically Endangered for S. teuszii).

Fast and Sustainable Determination of Persistent Organic Pollutants from Organic Fertilizer Using Optimized Microwave-Assisted Extraction Method and Gas Chromatography-Mass Spectrometry

A microwave-assisted extraction was optimized for the evaluation of persistent organic pollutants in liquid fertilizer samples. The extraction process was defined by a 23 factorial design. The parameters (temperature and sample and solvent volume) were optimized through the response surface methodology (RSM). The data for the study were based on injection of a mix of organochlorine pesticides. In optimized conditions, the microwave-assisted extraction was carried out at 70℃ for 10 minutes using 10 mL of sample and 10 mL of solvent. This study was accomplishment to evaluate the statistical influence of parameters: temperature, solvent volume and sample volume in the microwave-assisted extraction of organochlorine contaminants present in biofertilizer samples obtained from liquid humus and consequently to define the best conditions of process.

Organochlorine contaminants and polybrominated diphenyl ethers in eggs and embryos of Antarctic birds

AbstractOrganochlorine contaminants (OCs) and polybrominated diphenyl ethers (PBDEs) were investigated in the eggs of five bird species from the South Shetland Islands. Additionally, OCs and PBDEs were also analysed in embryos of two species. The concentration ranges in eggs were (ng g-1wet weight) 2.11 to 541 for polychlorinated biphenyls (PCBs), &lt;0.25 to 0.88 for PBDEs, 2.45 to 405 forp,p’-DDE and 1.50 to 603 for mirex. The PCBs were predominant in the eggs ofMacronectes giganteus,Catharacta antarcticaandLarus dominicanus, whereas hexachlorobenzene (HCB) was the major compound found in the eggs ofPygoscelis antarcticusandSterna vittata. The PBDE congeners were detected only in the eggs ofC. antarctica(PBDE 47 and 153) andS. vittata(PBDE 47). There were differences in OC concentrations of up to two orders of magnitude betweenM. giganteusembryos which were related to the development stage and OC concentrations in the respective eggs. Trophic ecology and post-breeding dispersal exerted an influence on contaminant patterns. Comparisons with data from the literature indicate an increase in the concentrations of some OCs over recent years.

Removal of Organochlorine Pesticides in Constructed Wetlands

Organochlorine pesticides have had a wide and long history of applications in many countries around the world, which cause serious environmental problems. Constructed wetlands are considered an effective means of removal of organochlorine pesticides. This study describes the constructed wetland and applications of organochlorine pesticides contamination in constructed wetlands, and focuses on purification for organochlorine pesticides of microorganisms and plants in constructed wetlands. Then discussed constructed wetlands removal influence factors of organochlorine pesticides. And put forward some recommendations in research.