Cis-heptachlor Epoxide Research Articles

First WHO/UNEP survey of the current concentrations of persistent organic pollutants in human milk in Morocco

The presence of persistent organic pollutants (POPs) in human milk is an indicator of the level of these substances in the environment and enables evaluation of the potential exposure of breastfed children. POPs concentrations in a Moroccan human milk pooled sample (59 donors) were determined for the first time by the WHO reference laboratory to provide a baseline and allow monitoring of the future trends for those persistent organohalogen compounds. Eighty-one different POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dioxins and furans (PCDD/Fs) were identified and quantified by using gas chromatography (GC) with an electron capture detector (ECD) and confirmed by gas chromatography-mass spectrometry (GC/LRMS). The obtained results showed that the sum of DDT (sum of o,p’-DDD, p,p′-DDD, o,p′-DDE, p,p′-DDE, o,p’-DDT, and p,p′-DDT) was 237.9 ng/g, representing 94.0% of all detected OCPs levels, with a dominance of p,p′-DDE, and p,p′-DDT. Cis-heptachlor epoxide, HCB, and HCH were found at much lower levels. PCB indicator level was 60.7 ng/g of lipid, with the dominance of PCB 138, PCB 153, and PCB 180, presenting 98.3% of the total. Among the 25 PBDE congeners quantified, BDE-47, BDE-153, BDE-197, and BDE-207 were the dominant congeners account for 15.4% of the total concentration of PBDE (1.3 pg/g lipid). The lipid-adjusted level of PCDD/Fs and dl-PCBs expressed in Toxic Equivalents (TEQs: 6.65 pg/g) were lower in comparison to those found in the other countries. In summary, detected POPs levels in Moroccan human milk were much lower compared to the other countries, reflecting the effectiveness of the compliance with Stockholm Convention requirements on eliminating or reducing emissions of selected POPs. Continued monitoring is needed for these compounds, for which this is the first data available, provided by the WHO/UNEP survey in Morocco.

Longitudinal changes in concentrations of persistent organic pollutants (1986-2016) and their associations with type 2 diabetes mellitus.

Positive associations have been reported between persistent organic pollutants (POPs) and type 2 diabetes mellitus (T2DM); however, causality has not been established. Over the last decades, environmental exposure to legacy POPs has decreased, complicating epidemiological studies. In addition, physiological risk factors for T2DM may also influence POP concentrations, contributing to a complex network of factors that could impact associations with T2DM. Longitudinal studies on this topic are lacking, and few have assessed prospective and cross-sectional associations between repeated POP measurements and T2DM in the same individuals, which may shed light on causality. To compare longitudinal trends in concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in T2DM cases and controls, and to examine prospective and cross-sectional associations between PCBs, OCPs and T2DM at different time-points before and after T2DM diagnosis in cases. We conducted a longitudinal, nested case-control study (1986-2016) of 116 T2DM cases and 139 controls from the Tromsø Study. All participants had three blood samples collected before T2DM diagnosis in cases, and up to two samples thereafter. We used linear mixed-effect models to assess temporal changes of POPs within and between T2DM cases and controls, and logistic regression models to investigate the associations between different POPs and T2DM at different time-points. PCBs, trans-nonachlor, cis-nonachlor, oxychlordane, cis-heptachlor epoxide, p,p'-DDE, and p,p'-DDT declined more slowly in cases than controls, whereas β-HCH and HCB declined similarly in both groups. Most POPs showed positive associations between both pre- and post-diagnostic concentrations and T2DM, though effect estimates were imprecise. These associations were most consistent for cis-heptachlor epoxide. The observed positive associations between certain POPs and T2DM may be because of higher POP concentrations within prospective T2DM cases, due to slower temporal declines as compared to controls.

Serum concentrations of persistent organic pollutants and colorectal cancer risk: A case-cohort study within Korean National Cancer Center Community (KNCCC) cohort

Background & aimsRecent prospective cohort studies have suggested that circulating persistent organic pollutants (POPs) may be associated with the development of cancers. We investigated the association between pre-diagnostic serum concentrations of POPs and colorectal cancer (CRC) risk. MethodsA case-cohort study within a community-based prospective cohort was performed, including 104 CRC cases and 235 subcohort participants. Serum concentrations of POPs were measured by high resolution gas chromatography/high-resolution mass spectrometry. Multivariable Cox proportional hazards regression models were used. ResultsThe association between serum concentrations of organochlorine pesticides (OCs) and CRC risk was significant (cis-heptachlor epoxide: 3rd tercile [HR (95% CI): 2.76 (1.25–6.07); trans-nonachlor: 2nd tercile [HR (95% CI): 3.90 (1.56–9.75)], 3rd tercile [HR (95% CI): 4.86 (1.95–12.16)]); p,p’-DDD: 2nd tercile [HR (95% CI): 6.02 (2.05–17.70)], 3rd tercile [HR (95% CI): 7.43 (2.42–22.84)]). Certain polychlorinated biphenyls (PCBs) congeners were significantly associated with CRC risk (PCB-105: 3rd tercile HR [95% CI]: 3.15 [1.38–7.19], PCB-118: 3rd tercile HR [95% CI]: 2.68 [1.22–5.92]; PCB-138: 2nd tercile [HR (95% CI): 2.51 (1.19–5.28)], 3rd tercile [HR (95% CI): 3.27 (1.50–7.12)]; PCB-153: 2nd tercile [HR (95% CI): 3.93 (1.81–8.54)], 3rd tercile [HR (95% CI): 5.02 (2.09–12.07)]; PCB-156: 2nd tercile [HR (95% CI): 2.61 (1.21–5.59)], 3rd tercile [HR (95% CI): 4.07 (1.73–9.61)]; PCB-180: 2nd tercile [HR (95% CI): 2.58 (1.15–5.78)], 3rd tercile [HR (95% CI): 4.01 (1.68–9.59)]).results ConclusionsThis study suggests that serum concentrations of POPs could increase the CRC risk in the general population.

Abstract A16: Environmental exposure to persistent organic pollutants (POPs) and primary colorectal cancer risk: A case-cohort study in a community-based perspective cohort

Abstract Background: Recent studies suggest that the low-dose environmental exposure of persistent organic pollutants (POPs) may develop prostate cancer or breast cancer based on prospective cohort study design. This study investigates a relationship between environmental exposures to POPs and the development of colorectal cancer (CRC) in the general population. Methods: We conducted a case-cohort study based on the Korean National Cancer Center Community Cohort, which included 16,304 adults who enrolled from 1993 to 2010 and followed by 2016 for the cancer incidence. We included 104 CRC cases and 235 adults in a subcohort and assessed their serum lipid-adjusted levels of 19 organochlorine pesticides (OCPs) and 32 polychlorinated biphenyls (PCBs). Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for determining the association between POPs and risk of CRC were estimated using logistic regression analyses, controlling for following covariates: age, sex, education, physical activity, meat consumption, vegetable/fruit consumption, drinking, smoking, obesity, pesticides use experience, and residential areas. Results: Natural log-transformed cis-heptachlor epoxide and p,p’-DDD were significantly associated with increased risk of CRC [ORcis-heptachlor epoxide = 1.29, 95% CI: 1.03-1.62; ORp,p’-DDD = 1.63, 95% CI: 1.11-2.41] and increased ORs were also estimated for the highest versus lowest tertiles of these two metabolites [ORcis-heptachlor epoxide = 2.64, 95% CI: 1.24-5.6, p-trend = 0.021; ORp,p’-DDD = 3.51, 95% CI: 1.58-7.78, p-trend = 0.004]. Also, there was a significant association between natural log-transformed PCB 52 and risk of CRC (ORPCB 52 = 1.54, 95% CI: 1.06-2.24). Conclusion: Higher exposure to POPs, such as cis-heptachlor epoxide, p,p’-DDD, and PCB 52, was associated with the elevated risk of CRC. Our findings from a community-based prospective cohort provide evidence on the relationship between environmental exposure of POPs and CRC in the general population. Citation Format: Jinsun Kim, Eun Young Park, Byungmi Kim, Min Kyung Lim, Jin-Kyoung Oh. Environmental exposure to persistent organic pollutants (POPs) and primary colorectal cancer risk: A case-cohort study in a community-based perspective cohort [abstract]. In: Proceedings of the AACR Special Conference on Environmental Carcinogenesis: Potential Pathway to Cancer Prevention; 2019 Jun 22-24; Charlotte, NC. Philadelphia (PA): AACR; Can Prev Res 2020;13(7 Suppl): Abstract nr A16.

Associations between persistent organic pollutants and endometriosis: A multipollutant assessment using machine learning algorithms

Endometriosis is a gynaecological disease characterised by the presence of endometriotic tissue outside of the uterus impacting a significant fraction of women of childbearing age. Evidence from epidemiological studies suggests a relationship between risk of endometriosis and exposure to some organochlorine persistent organic pollutants (POPs). However, these chemicals are numerous and occur in complex and highly correlated mixtures, and to date, most studies have not accounted for this simultaneous exposure. Linear and logistic regression models are constrained to adjusting for multiple exposures when variables are highly intercorrelated, resulting in unstable coefficients and arbitrary findings. Advanced machine learning models, of emerging use in epidemiology, today appear as a promising option to address these limitations. In this study, different machine learning techniques were compared on a dataset from a case-control study conducted in France to explore associations between mixtures of POPs and deep endometriosis. The battery of models encompassed regularised logistic regression, artificial neural network, support vector machine, adaptive boosting, and partial least-squares discriminant analysis with some additional sparsity constraints. These techniques were applied to identify the biomarkers of internal exposure in adipose tissue most associated with endometriosis and to compare model classification performance. The five tested models revealed a consistent selection of most associated POPs with deep endometriosis, including octachlorodibenzofuran, cis-heptachlor epoxide, polychlorinated biphenyl 77 or trans-nonachlor, among others. The high classification performance of all five models confirmed that machine learning may be a promising complementary approach in modelling highly correlated exposure biomarkers and their associations with health outcomes. Regularised logistic regression provided a good compromise between the interpretability of traditional statistical approaches and the classification capacity of machine learning approaches. Applying a battery of complementary algorithms may be a strategic approach to decipher complex exposome-health associations when the underlying structure is unknown.

Root uptake and translocation of 14C-heptachlor and its degradation products in soil by zucchini and tomato seedlings.

To investigate root uptake and translocation of heptachlor and its degradates (cis-heptachlor epoxide and 1-hydroxychlordene) in soil, zucchini and tomato seedlings were transplanted to soil approximately four months after treatment with 14C-heptachlor. The results indicated that a relation between the root concentration factor and the log P ow did not follow Briggs' theory, probably due to the contribution of plant metabolism. It also appeared that a compound with a lower log P ow tends to show higher mobility from root to shoot.

Association between prenatal exposure to organochlorine pesticides and the mental and psychomotor development of infants at ages 6 and 18 months: The Hokkaido Study on Environment and Children’s Health

Organochlorine pesticides (OCPs) are environmental contaminants that persist in the environment and bioaccumulate through the food chain in humans and animals. Although previous studies have shown an association between prenatal OCP exposure and subsequent neurodevelopment, the levels of OCPs included in these studies were inconsistent. A hospital-based prospective birth cohort study was conducted to examine the associations between prenatal exposure to relatively low levels of OCPs and neurodevelopment in infants at 6 (n=164) and 18 (n=115)months of age. Blood samples were analyzed using gas chromatography/mass spectrometry techniques to quantify 29 OCPs. The Bayley Scales of Infant Development 2nd edition (BSID-II) was used to assess the Mental and Psychomotor Developmental Index. After controlling for confounders, we found an inverse association between prenatal exposure to cis-heptachlor epoxide and the Mental Developmental Index at 18 months of age. Furthermore, infants born to mothers with prenatal concentrations of cis-heptachlor epoxide in the highest quartile had Mental Developmental Index scores −9.8 (95% confidence interval: −16.4, −3.1) lower than that recorded for infants born to mothers with concentrations of cis-heptachlor epoxide in the first quartile (p for trend <0.01). These results support the hypothesis that prenatal exposure to OCPs, especially cis-heptachlor epoxide, may have an adverse effect on the neurodevelopment of infants at specific ages, even at low levels.

Association between serum persistent organic pollutants and DNA methylation in Korean adults

BackgroundExposure to persistent organic pollutants (POPs) has been associated with epigenetic changes such as DNA methylation, which can influence human health. However, the association between POPs and DNA methylation by sex was not shown in previous studies. ObjectivesWe investigated the association between POPs and DNA methylation in men and women using a larger population. MethodsA cross-sectional study was conducted using the data of 444 Koreans (253 men and 191 women). Measurements for sixteen different POPs, including six organochlorine pesticides (OCPs) and ten polychlorinated biphenyls (PCBs) were taken in serum. DNA methylation via Alu and LINE-1 in peripheral leukocytes was measured by pyrosequencing. To evaluate the association between POPs and DNA methylation, the Pearson's correlation and multiple linear regression analyses were performed. ResultsExcept for PCB52 and PCB101, we found significant inverse associations between p,p’-DDE, cis-Heptachlor epoxide, and PCBs and Alu assay in men after adjusting for age, BMI, smoking status, and alcohol consumption (β = −0.67 for p,p′-DDE; −0.28 for cis-Heptachlor epoxide; in the range from −0.43 to −1.60 for PCBs). In women, PCB153 and PCB180 showed statistically significant inverse association with Alu assay (β = −0.22 for PCB153; −0.22 for PCB180). Except for PCB101, p,p′-DDE and PCBs were positively associated with LINE-1 assay in women (β = 0.48 for p,p′-DDE; in the range from 0.40–0.89 for PCBs) while p,p′-DDE, PCB153, and PCB180 showed positive associations with LINE-1 assay in men (β = 0.55 for p,p′-DDE; 0.65 for PCB153; 1.02 for PCB180). ConclusionsWe found that several POPs were associated with global DNA hypomethylation in the Alu assay for men and global DNA hypermethylation in the LINE-1 assay for women.

Persistent organic pollutants in shallow percolated water of the Alps Karst system (Zugspitze summit, Germany)

In the German Calcareous Alps at the Zugspitze, percolated water close to a permafrost bedrock in a tunnel system was monitored long-term for polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzofurans (PCDF), polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), and 28 organochlorine pesticides (OCP). Semi-permeable membrane devices (SPMD) were deployed in a temporary surface water system at the Zugspitze plateau and analysed for PCB, PAH, and OCP. The high-volume water sampling was successfully implemented and all compounds were identified in the water percolated through the Karst system. However, the percentage distribution of contaminants in the percolated water differed significantly from that found in surface waters. The highest chlorinated PCDD homologues were the predominant compounds of the PCDD/F family, whereas percentages of PCB #52 increased in percolated water. Toxic equivalent values (TEQ) of samples ranged from 2.0 to 4.2pgTEQ/m3 and from 0.017 to 0.069pgTEQ/m3 for PCDD/F and PCB, respectively. Low and intermediate molecular weight PAH were the prevailing compounds in the samples. Endosulfan sulfate, endrin, and cis-heptachlor epoxide were enhanced after water percolation through the Karst system in comparison with the surface waters (wet deposition). The relative enrichment on these pesticides was related to the environmental bedrock conditions and glacier melting sources. In summary, the Karst system highly influenced the fate of organic persistent pollutants generating different chemical patterns in their percolated waters than those found at the surface systems.

한국 성인의 혈청 잔류성 유기오염물질 농도와 연령 및 체질량지수와의 관련성

Objectives: Persistent organic pollutants (POPs) are known to be the detrimental chemicals in the body, even at low levels, and are stored in adipose tissue. Recently, POPs have been reported to be associated with chronic diseases, including cancer and cardiovascular disease, and aging and obesity are reported as common factors in chronic disease. However, there have been only a few studies on the associations of POPs with age and body mass index (BMI) in Korea. Therefore, we analyzed the associations of serum POPs levels with age and BMI in Korea. Methods: This cross-sectional study includes 444 subjects (253 men and 191 women) from the Korean Cancer Prevention Study-II (2004-2011). Serum levels of 33 polychlorinated biphenyls (PCBs) and 19 organochlorine pesticides (OCPs) were measured by a gas chromatographer (Agilent 6890) coupled to high resolution mass spectrometer (JEOL JMS-800D). Results: Concentrations of PCB 153 (men: 12.26 ng/g lipid, women: 10.50 ng/g lipid) and p,p`-DDE (men: 94.66 ng/g lipid, women: 96.66 ng/g lipid) were the highest among serum PCBs and OCPs, respectively. PCBs and OCPs were significantly positively correlated with age in both sexes. After adjustment for age, non-dioxin like PCBs were significantly negatively correlated with body mass in women. However, cis-heptachlor epoxide was significantly positively correlated with body mass index in both sexes. When analyzed by sex, stronger associations were shown between POPs and age in men and POPs and BMI in women. Conclusion: These results may provide baseline data for the study of POPs and for the health management field in Korea.

Degradation of the Persistent Organic Pollutant [14C]Heptachlor in Japanese Field Soils

The fate of [(14)C]heptachlor in Saitama soil and the degradation of [(14)C]heptachlor in four Japanese field soils over 112 d after application were investigated. Heptachlor was degraded mainly to cis-heptachlor epoxide by a biotic process and to 1-hydroxychlordene by an abiotic process in the field soils. Volatilization of heptachlor and cis-heptachlor epoxide from the soil was observed over the experimental period. The amount of 1-hydroxychlordene produced in the soils appeared to be related to the soil water contents. Because heptachlor and heptachlor epoxides are predicted to volatilize to the atmosphere and to persist in soils, these compounds are thought to spread among Japanese environmental compartments even after a ban on their use.

Intrinsic bioavailability of 14C-heptachlor to several plant species

To investigate the intrinsic bioavailability of heptachlor to various plant species, the root of each test plant was treated with hydroponic solution containing 14C-heptachlor for 72 hr. The levels and nature of 14C-residues in roots and shoots of treated plants were determined to estimate the values of the root concentration factor (RCF) and the transpiration stream concentration factor (TSCF). RCF and TSCF values ranged from 126 (corn) to 4086 (lettuce) and 0.052 (Chinese cabbage) to 0.494 (zucchini), respectively. In pumpkin and zucchini, unmetabolized heptachlor itself was translocated from the root to the shoot via a transpiration stream and no further extensive metabolism was observed. cis-Heptachlor epoxide was the predominant metabolite in the shoots of tomato, cabbage, Chinese cabbage and lettuce. Less metabolism of cis-heptachlor epoxide was suggested in the shoots of these plants.

Determination of some organochlorine pesticide residues in honeys from Konya, Turkey

In this study, 24 organochlorine pesticide residues in 109 different honey samples collected from stores and open markets in Konya, Turkey were analyzed by gas chromatography-electron capture detection. Aldrin, cis-chlordane, trans-chlordane, oxy-chlordane, 2,4(')-DDE, and 4,4(')-DDE were found in all honey samples. The mean value was 0.0540 microg g(-1) for oxy-chlordane. In the 55 samples of 109, levels of organochlorine pesticide residues of oxy-chlordane were determined as higher than those of Turkish Alimentarius Codex maximum residual limits (MRLs). Other organochlorine pesticide residues also exceeded MRLs except for cis-heptachlor epoxide and alpha-hexachlorocyclohexane. Since all of the honey samples are found contaminated and most of these samples exceeded MRLs, a control of organochlorine pesticide residues in honey is necessary for consumer health.

From mother to child: Investigation of prenatal and postnatal exposure to persistent bioaccumulating toxicants using breast milk and placenta biomonitoring

The exposure levels of placenta and paired breast milk samples to selected organochlorine compounds and pesticides from Danish and Finnish samples have been investigated. p,p'-DDE is the dominant pollutant, beta-HCH, hexachlorobenzene, endosulfan-I, dieldrin, oxychlordane, cis-heptachlor epoxide and p,p'-DDT being the other major constituents. Their concentrations are linearly correlated between milk and placenta in similar patterns for Danish and Finnish samples. Milk samples have higher levels of these pollutants than placenta on lipid base. However, the apparently not correlated compounds, such as alpha-HCH, pentachlorobenzene, pentachloroanisole and methoxychlor, are generally accumulated more in placenta, which may suggest a tissue specific metabolic activity. Thus, depending on the compound of interest, biomonitoring may be done in placenta only or in both matrices.

Chiral organochlorine pesticides in the atmosphere

We measured the enantiomeric fractions (EF) of various organochlorine pesticides in air samples from Indiana, Arkansas, and Louisiana collected in 2002–2003. Enantiomeric fractions for o,p′-DDD are reported here for the first time, and they suggest preferential depletion of one enantiomer over the other, with a mean value of 0.44. For the chlordanes, the EFs followed the same trends as reported in previous studies. EF values for trans-chlordane (TC) were slightly below 0.5, and values for cis-chlordane (CC) were slightly above 0.5. For cis-heptachlor epoxide (HEPX), the EF values averaged 0.65, indicating a clear preferential depletion of the (−)-enantiomer. For TC and CC, no clear distinction could be made between the values measured among the three sites, suggesting that it is not possible to use these EF values as “source signatures”. For HEPX, the Indiana site had significantly higher EF values than did the Arkansas site; this difference may reflect differences in the historic use of heptachlor in these two regions.

Enantioseparation of Chiral Organochlorines on Permethylated - and -Cyclodextrin, as well as 1:1 Mixtures of Them

Gas chromatography columns coated with 10% permethylated beta- and gamma-cyclodextrin in 85% dimethyl-15% diphenyl polysiloxane (beta- and gamma-PMCD, respectively) and 1:1 mixures are prepared and tested with regard to the enantioseparation of chiral chloropesticides. On the columns with the individual O-methylated cyclodextrins (O-tCDs), the enantiomers of aaeeee-hexachlorocyclohexane (alpha-HCH), e-aeee-1,3,4,5,6-pentachlorocyclohex-1-ene (beta-PCCH), and e-aaee-1,3,4,5,6-pentachlorocyclohex-1-ene (gamma-PCCH), cis- and trans-chlordane, and cis-heptachlor epoxide are separated on both columns, with the exception of the latter being separated only on beta-PMCD. On the column coated with 5% beta- and 5% gamma-PMCD, the resulting separation factor (a) is virtually 1/2 of the arithmetric mean of the elution-dependent separation factors on the individual O-tCDs. In case of reversed elution order on beta- and gamma-PMCD, the enantiomers are not resolved on the mixed columns as is the case with cis-chlordane. Likewise, the lower resolution of the gamma-PCCH enantiomers on the mixed columns prove the reversed elution order on beta- and gamma-PMCD without having enantioenriched standards available. On the column coated with 5% beta- and 5% gamma-PMCD, similar retention times to those observed on both 10% beta-PMCD and 10% gamma-PMCD are obtained. On the column coated with 10% beta- and 10% gamma-PMCD, significantly longer retention times are obtained compared with the columns that contain a total of 10% chiral stationary phase (CSP). This indicates that a relevant part of the interaction of the analytes with the chiral selector is non-enantioselective and, thus, only delays the elution of both enantiomers. Moreover, these non-enantioselective interactions prevent a direct comparison of CSPs with different amounts of the chiral selector. However, this is possible by using mixed phases of two CSPs with similar properties. Using this system, it is demonstrated that for the organochlorine compounds studied, no higher separation factor is observed on the mixed CSPs than on the individual O-tCD with the higher separation factor. Estimations allow a prediction that enantioseparations of organohalogen compounds can be achieved on columns coated with as little as 1% of the CSP.

Chlorinated cyclodiene pesticide residues in blue mussel, crab, and fish in the Gulf of Gdańsk, Baltic Sea.

Chlordane components (CHLs) and their metabolites (heptachlor, cis-heptachlor epoxide, U82, MC4, trans-chlordane, MC5, cis-chlordane, MC7, oxychlordane, MC6- and trans- and cis-nonachlor) and aldrin, dieldrin, endrin, isodrin, endosulfan 1, endosulfan 2, and mirex were quantified in the soft tissues of blue mussel, a whole crab, and whole fishes collected from the spatially different sites in the Gulf of Gdańsk. Six to twelve chlordane compounds and metabolites and dieldrin were detected in all organisms examined while aldrin, endrin, isodrin, endosulfans 1 and 2, and mirex were not found above the detection limit of the method. The lipid weight based concentrations in Baltic biota were relatively small and ranged from 12 to 150 and 7.6-77 ng/g, while between 0.16 and 6.8 and 0.10-6.6 ng/g in fresh tissue, respectively. The profile (%) of chlordane compounds was very similar between various fish species with trans-nonachlor (28 +/- 17), cis-chlordane (23 +/- 18), oxychlordane (13 +/- 7), and heptachlor epoxide (11 +/- 5) as major constituents and was totally different in crab with oxychlordane as the most dominating (>65%) compound. Blue mussel, lamprey, and three-spined stickleback exhibited a smallest ability to metabolize CHLs, and such fishes as cod, lesser sand-eel, sand-eel, pikeperch, perch, round goby, flounder, and herring showed a slightly better ability, while crab was able to effectively metabolize most of CHL compounds except trans-nonachlor. A value of the quotient of the trans-nonachlor to cis-chlordane concentrations (N/C quotient) was 1.0 in blue mussel, 3.1 in crab, and between 0.9 and 1.8 in fish. Both the small concentrations of CHLs in all organisms and the values of N/C quotients close to 1 imply on a long-range aerial transport through movement of the air masses from the remote regions of the northern hemisphere as a main source of this pesticide in the Gulf of Gdańsk. The interdependences between the CHL profiles for various fish species and between different sampling sites were examined using the principal component analysis (PCA) method. Applying the PCA model the first four significant components explained 90% (43% + 23% + 15% + 8%) of the total variance in the data matrix.

PCDDs, PCDFs, PCBs, and Other Organochlorine Compounds in Human Milk from Rio de Janeiro, Brazil

The levels of polychlorinated dibenzo-p-dioxins (PCDDs) and -furans (PCDFs), polychlorinated biphenyls (PCBs), and other organochlorine compounds were determined in a pooled sample of breast milk from 40 mothers (first lactation: 33; second lactation: 7, age: 15–38 years) living in the urban area of Rio de Janeiro County, Brazil, in 1992. Mothers were breast-feeding only one infant and milk was collected between 4 and 6 weeks after delivery. The results showed a dioxin equivalent concentration of 8.1 pg I-TEq/g milk fat. The levels of other chlorinated compounds (micrograms per gram of milk fat) were as follows: PCBs (total), 0.15; α-HCH, 0.001; β-HCH, 0.27;γ-HCH, 0.005; HCB, 0.012; DDT (total), 1.7; dieldrin, 0.023, and cis-heptachlor epoxide, 0.008. These results suggest that human background contamination by PCDD/Fs, PCBs, and HCB in Rio de Janeiro is lower than that generally found in industrialized countries.

Contamination of game in Schleswig-Holstein. 2. Residues of dieldrin, heptachlor epoxide and other cyclodiene insecticides in the liver fat of hares (Lepus europaeus L.)

Increased levels of Dieldrin (0.01-2.94 mg/kg fat, median mean = 0.38 mg/kg fat) and cis-Heptachlor Epoxide (less than 0.01-1.38 mg/kg fat, mean = 0.20 mg/kg fat) were determined by GC/ECD in liver fat of 199 hares (Lepus europaeus L.) from Schleswig-Holstein, North Germany. This investigation was carried out within the scope of a game investigation program. The dependence of these residues on endogenous and exogenous factors are discussed. Oxychlordane and trans-Nonachlor, residues of Chlordane, were also analysed in liver fat by GC/MS. The application of the cyclodiene insecticides Aldrin/Dieldrin, Heptachlor and Chlordane has been prohibited in West Germany for several years; the residues indicate the high soil persistence of these substances.