Higher DDE Levels Research Articles

Systematic investigation of organochlorine pesticides and polychlorinated biphenyls blood levels in Greek children from the Rhea birth cohort suggests historical exposure to DDT and through diet to DDE

The blood levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been thoroughly investigated in Greek children from the Rhea birth cohort study. This investigation aimed to assess exposure levels, explore their possible relationship with children's age and sex, and indicate potential sources of exposure. Exposure patterns and common sources of PCBs and OCPs were analyzed using bivariate and multivariate statistics.A total of 947 blood samples from study participants were analyzed for OCP and PCB exposure, with 375 samples collected at 4 years old, 239 at 6.5 years old, and 333 at 11 years old. Elevated levels of DDE were observed in 6.5-year-old children compared to corresponding levels in other European countries. Higher levels of DDE were found in 4-year-old children, with the lowest concentrations in the 11-year-old group. The DDT/DDE ratio was consistently less than 1 among all the examined subjects. These results indicate exposure to DDT and DDE both in utero and through breastfeeding and dietary intake. For the entire cohort population, the highest concentration was determined for PCB 28, followed by PCBs 138, 153, and 180. The sum of the six indicator PCBs implied low exposure levels for the majority of the cohort population. Spearman correlations revealed strong associations between PCBs and OCPs, while principal component analysis identified two different groupings of exposure. DDE exhibited a correlation with a series of PCBs (153, 156, 163, 180), indicating a combined OCP-PCB source, and an anticorrelation with others (52, 28, 101), implying a separate and competing source.

Organochlorine pesticide levels in Greek patients with Parkinson’s disease

BackgroundParkinson’s disease (PD) is a neurodegenerative disease, mostly presenting with characteristic motor symptoms. Organochlorines (OC) are a class of widely-used pesticides that have been included among the list of environmental factors incriminated in PD pathogenesis. However, most studies reporting this association are based on questionnaires, and few have reported exposure data. AimTo examine the relationship between OC blood concentrations and PD risk. MethodsIn the present study, we studied the concentrations of 8 OC compounds (hexachlorobenzene, heptachlor, hepachlor epoxide, c-chlordane, a-chlordane, p,p’-DDE, DDD, DDT) in 104 Greek PD patients and 110 healthy controls. ResultsAll substances studied were present in at least one sample. The most frequently detected (above the level of quantification) pesticides were p,p’-DDE (n = 214, 100 % of both groups) and hexachlorobenzene, HCB (n = 189, cases 46.5 %, controls 53.5 %). Higher levels of DDE were detected among PD patients in comparison to controls by using logistic regression analysis to control for confounders [Odds Ratio, OR (95 % confidence interval, C.I.)]: 2.592,(1.29–5.21)], whilst lower levels of HCB were detect among PD patients [OR,95 %CI:0.176(0.09−0.35)]. ConclusionsOur data suggest that exposure to specific OCs is related to the risk of PD. Further studies, using real exposure data, are needed in order to confirm and extend these findings.

Levels of organochlorine pesticides in the blood of people living in areas of intensive pesticide use in Sudan.

Ninety-six human blood samples were collected from six locations that represent areas of intensive pesticide use in Sudan, which included irrigated cotton schemes (Wad Medani, Hasaheesa, Elmanagil, and Elfaw) and sugarcane schemes (Kenana and Gunaid). Blood samples were analyzed for organochlorine pesticide residues by gas liquid chromatography (GLC) equipped with an electron capture detector (ECD). Residues of p,p'-dichlorodiphenyldichloroethylene (DDE), heptachlor epoxide, γ-HCH, and dieldrin were detected in blood from all locations surveyed. Aldrin was not detected in any of the samples analyzed, probably due to its conversion to dieldrin. The levels of total organochlorine burden detected were higher in the blood from people in the irrigated cotton schemes (mean 261 ng ml(-1), range 38-641 ng ml(-1)) than in the blood of people from the irrigated sugarcane schemes (mean 204 ng ml(-1), range 59-365 ng ml(-1)). The highest levels of heptachlor epoxide (170 ng ml(-1)) and γ-HCH (92 ng ml(-1)) were observed in blood samples from Hasaheesa, while the highest levels of DDE (618 ng ml(-1)) and dieldrin (82 ng ml(-1)) were observed in blood samples from Wad Medani and Kenana, respectively. The organochlorine levels in blood samples seemed to decrease with increasing distance from the old irrigated cotton schemes (Wad Medani, Hasaheesa, and Elmanagil) where the heavy application of these pesticides took place historically.

Organochlorine compounds in red deer (Cervus elaphus L.) and fallow deer (Dama dama L.) from inland and coastal Croatia

Polychlorinated biphenyl (PCB) and organochlorine pesticide (OCP) levels in fat tissue of red and fallow deer (Cervus elaphus L. and Dama dama L.) from two inland and an Adriatic area were established. Of 17 analysed PCBs, PCB-28, PCB-138, PCB-153, PCB-180 and PCB-118 were found in all samples, whilst PCB-101 and PCB-170 were found in more than 50% of samples. They ranged between 0.03 and 5.98 ng g(-1) fat weight. Of seven analysed OCPs, HCB, γ-HCH and 1,1-dichloro-2,2-di(4-chlorophenyl)ethylene (DDE) were found in all samples, whilst β-HCH was found in more than 50% of samples. They ranged between 0.17 and 22.14 ng g(-1) fat weight. The dominating compounds were DDE, PCB-138, PCB153, PCB-118 and PCB-180. According to the Duncan multistage test, the levels of PCB-138, PCB-153, PCB 170 and PCB-180 were significantly higher in perirenal fat samples of specimens taken from the Adriatic area. DDE was significantly higher in the inland deer samples. Some species differences were determined and were mostly related to higher PCB and β-HCH levels in fallow deer samples and higher DDE levels in red deer samples. No sex difference was established. As for age, significantly higher levels of PCB-118 and PCB-52 were found in fawns.

Programmed Obesity?: Study Links Intrauterine Exposures to Higher BMI in Toddlers

Vol. 117, No. 1 EnvironewsOpen AccessProgrammed Obesity?: Study Links Intrauterine Exposures to Higher BMI in Toddlers M. Nathaniel Mead M. Nathaniel Mead Search for more papers by this author Published:1 January 2009https://doi.org/10.1289/ehp.117-a33bAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit To date, there have been relatively few epidemiologic studies investigating the association between intrauterine exposure to chemicals and body mass index (BMI, which characterizes weight in relation to height). Now a prospective birth cohort study in Flanders, Belgium, reveals an association between prenatal exposure to environmental pollutants and elevated BMI during the first three years of life [EHP 117:122–126; Verhulst et al.]. The study also found associations between exposures and birth weight and length.Since the late 1990s, developmental biologists have amassed laboratory data indicating that exposure to endocrine disruptors such as polychlorinated biphenyls (PCBs), dioxins, and bisphenol A during critical phases of fetal development may increase the risk of obesity later in life. In addition, prenatal exposure to cigarette smoke has been linked with the subsequent development of obesity. These exposures likely alter mechanisms involved in weight homeostasis.Using a longitudinal study design, the researchers obtained a random sample of 138 mother–infant pairs by drawing from 26 maternity wards in Flanders between September 2002 and February 2004. These wards were identified within geographic areas with varying environment and pollution characteristics (rural, urban, and industrial). The researchers collected information on the parents that included health status, smoking behavior, age, family composition, socioeconomic status, height, and weight. Children’s height and weight were also analyzed, and umbilical cord blood was collected to enable measurement of levels of hexachlorobenzene, dioxin-like compounds, PCBs, and the pesticide metabolite DDE. Children were then observed over a 3-year period.The main findings were twofold. First, higher PCB congener levels were associated with higher BMI standard deviation scores (SDS) in the children between 1 and 3 years of age. Both maternal smoking and higher PCB levels were positively associated with birth weight SDS. In addition, they showed a statistically significant combined effect. Second, higher DDE levels were associated with a slight increase in BMI SDS in 3-year-old children of nonsmoking mothers, but this effect was further increased in children of smoking mothers. Thus, simultaneous intrauterine exposure to endocrine disruptors might compound the weight-enhancing effects of maternal smoking during pregnancy.The researchers acknowledge a number of study limitations, including the fact that maternal weight gain during pregnancy—an important risk factor for obesity in children—was not recorded in the study. Additionally, the children were only followed for 3 years. Although it remains to be seen whether BMI trends for this particular study population will persist later in life, a higher BMI during toddlerhood is known to be associated with an increased risk of obesity in adulthood.This is the first epidemiologic study to demonstrate the impact of prenatal pollution exposure on BMI during the preschool years, and more large-scale prospective studies are certainly warranted. One research challenge will be to determine which factors mediate the effects of prenatal exposure to endocrine disruptors in terms of subsequent weight dysregulation in the offspring.Certain exposures in utero can affect birth weight, birth length, and later, body mass index.FiguresReferencesRelatedDetails Vol. 117, No. 1 January 2009Metrics About Article Metrics Publication History Originally published1 January 2009Published in print1 January 2009 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Intrauterine exposure to environmental pollutants and body mass index during the first 3 years of life.

ObjectiveWe investigated the association between body mass index (BMI) standard deviation score (SDS) and prenatal exposure to hexachlorobenzene, dichlorodiphenyldichloroethylene (DDE), dioxin-like compounds, and polychlorinated biphenyls (PCBs).MethodsIn this prospective birth cohort study, we assessed a random sample of mother–infant pairs (n = 138) living in Flanders, Belgium, with follow-up until the children were 3 years of age. We measured body mass index as standard deviation scores (BMI SDS) of children 1–3 years of age as well as pollutants measured in cord blood.ResultsDDE correlated with BMI SDS, with effect modification by maternal smoking and the child’s age. At 1 year, children of smoking mothers had higher BMI SDS than did children of nonsmoking mothers. At 3 years, this difference was reduced because of the faster rate of decline in BMI SDS in the former group. This relationship held except for children with high levels of DDE. DDE had a small effect on BMI SDS at 3 years of age in children of nonsmoking mothers (difference in BMI SDS for DDE concentrations between the 90th and 10th percentiles = 0.13). On the other hand, smoking enhanced the relation between DDE and BMI SDS at 3 years (difference in BMI SDS for DDE concentrations between the 90th and 10th percentiles = 0.76). Increasing concentrations of PCBs were associated with higher BMI SDS values at all ages (parameter estimate = 0.003 ± 0.001; p = 0.03).ConclusionIn this study we demonstrated that intrauterine exposure to DDE and PCBs is associated with BMI during early childhood. Future studies are warranted to confirm our findings and to assess possible mechanisms by which these pollutants could alter energy metabolism.

DDT, DDE and DDD in Human Milk from South Africa

Human breast milk samples (n=30) were collected from mothers within the age range of 19-40 years from Thohoyandou area, South Africa. DDT and its metabolites were extracted from the milk samples using diethyl ether. The crude extracts were subjected to column chromatography. The eluates were then evaporated on a stream of nitrogen up to 0.5 mL. One microliter of the cleaned extracts were injected into GC-ECD for selected organochlorine compounds. The sum total of DDT and its metabolites from each village ranged from not detectable for DMS, GNN and THN to 1,930 ng g(-1) fat wt for BDL while SigmaDDE ranged from 1.32 ng g(-1) fat wt for GNN to 2,570 ng g(-1) fat wt for TKD. SigmaDDD ranged from not detectable for GNN to 4,060 ng g(-1) fat wt for MNN. SigmaDDE was the most predominant followed by SigmaDDD and finally SigmaDDT. This was an indication of breakdown of the parent compound, DDT. Some villages namely, Lufule and Budeli, and Maniini and Makhuvha exhibited similar DDT occurrence of 89% in their areas. Other villages, DMS, TLM, and MND and TKD showed a similarity percentage of 82% while others showed similarities of 75% for GNN and MTT, 69% and 65% for MPG and THN respectively. A significant cluster of DDT and its metabolites between the infants' weight range of 2.5-3.9 kg/body wt was observed. Increase in lipid content was followed by a decrease in the sum DDT in the older mothers (27-30). The estimated daily intake varied from 260 to 4,696 ng/g, nd-10,551 ng/g and nd-4,237 ng/g for DDE, DDD and DDT respectively. These values are significantly (p<0.05) higher than the FAO/WHO acceptable daily intake (ADI) of 20 ng/g. The SigmaDDT was found to decrease with increasing age of the mothers. The observed high levels of DDE compared to DDT indicated chronic exposure of the mothers to DDT, which is metabolised to DDE and retained in the body.

Organochlorine residues in maternal milk from inhabitants of the Thohoyandou area, South Africa

The presence of organochlorine compounds (OC) such as DDT and their metabolites in the environment have created a significant environmental concern over the years due to adverse effects. Consequently, DDT has been banned in many countries. However, it is still used in some countries including South Africa, particularly for vector-borne disease eradication programmes. Since the presence of DDT and its metabolites may provide an indication of the general exposure and use of these compounds, there was a need for such a study. Human breast milk samples (n = 30) were collected from mothers within the age range of 19–40 years from the Thohoyandou area, South Africa. The liquid–liquid extraction method was used to extract DDT and its metabolites from the samples. The crude extracts were subjected to column chromatography for measurements of OC levels. The concentration ranges of the contaminants were as follows: not detected (ND) to1770 ng g−1 (2,4′-DDE); ND to 3977 ng g−1 (4,4′-DDE); ND to 3250 ng g−1 (2,4′-DDD); ND to 2580 ng g−1 (4,4′-DDD) and ND to 2847 ng g−1 (4,4′-DDT). The mean ΣDDE, ΣDDD and ΣDDT obtained from the villages were 1180 ng g−1, 830 ng g−1 and 690 ng g−1, respectively. The total DDT ranged from 820–7473 ng g−1. The estimated daily intake varied from 260 to 4696 ng g−1, ND-10551 ng g−1 and ND-4237 ng g−1 for DDE, DDD and DDT, respectively. These values are significantly higher than the FAO/WHO acceptable daily intake (ADI) of 20 ng g−1. The ΣDDT was found to decrease with increasing age of the mothers. The observed high levels of DDE compared to DDT indicated chronic exposure of the mothers to DDT, which is metabolized to DDE and retained in the body.

Menstrual cycle characteristics in European and Inuit women exposed to persistent organochlorine pollutants

Previous inconsistent results suggest that menstrual cycles may be disturbed by exposure to polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (DDE). Information on menstrual cycle characteristics were obtained by questionnaires, and PCB and DDE were measured in serum samples from a total of 1494 women from Greenland, Swedish fishermen's wives, and inhabitants of Warsaw in Poland and Kharkiv in Ukraine. No consistent effects of PCB and DDE exposure on menstrual cycle characteristics were observed across populations. Within populations, we observed increased risks of short cycles (< or =24 days) among Swedish fishermen's wives exposed to high levels of PCB [odds ratio (OR) 2.5, confidence interval (CI) 1.2-5.1], and increased risk of long cycles (> or =32 days) among Polish women exposed to high levels of DDE (OR 3.1, CI 1.1-8.6). However, in Greenland it seemed that high levels of PCB or DDE were protective against long menstrual cycles (OR 0.7 CI 0.5-0.96 and OR 0.7 CI 0.5-0.99, respectively). It is unlikely that exposure to PCB and DDE is a main cause of menstrual disturbances. Genetic differences or dietary factors may be involved in the non-homogenous associations of organochlorine exposure and menstrual cycle between countries.

Associations Between Thyroid Hormone Levels and Biomarkers of Exposure to DDT and DDE in Mexican-Americans

P-591 Introduction: Exposure to environmental chemicals has been associated with a range of adverse health effects, including effects on thyroid hormone levels in animals and humans. The organochlorine pesticides, including DDT and its environmental contaminant DDE, are among the chemicals associated with hormonal effects, including thyroid hormones. Thyroid hormone is critical for normal growth and development, and alterations in thyroid hormone levels may have significant health implications. Methods: The U.S. National Health and Nutrition Examination Survey (NHANES) collected blood DDT and DDE concentrations and thyroxin and thyroid stimulating hormone levels from 1999–2002 from a statistical sample of about 4,200 persons in the U.S. We analyzed these data to study the associations between exposure to DDT and DDE and levels of thyroxin and thyroid stimulating hormone in the U.S. population and selected subpopulations defined by country of origin, demographic characteristics, socioeconomic status, and geographic region. Results: DDE was above the limit of detection in the blood of 99.9% of the sampled persons. Mexican- born Americans have an arithmetic mean of 2310 ng/g (95% confidence interval 1814–2807), while the U.S. born have an arithmetic mean of 473 ng/g (417–528). Older persons have higher DDE levels, reflecting the history of the use of DDT. Pearson and Spearman correlations between DDE and thyroid hormone levels were computed for selected subsets of the U.S. population. Most of the correlations were low in magnitude, although some were statistically significant. In this type of study a causal association cannot be established. Discussion: While most of these factors exhibited little influence on the association between DDE and hormone levels, county of origin exibited a significant association. Specifically, U.S. residents born in Mexico had substantially higher levels of DDT and DDE than any other group, including Mexican-Americans born in the U.S. The findings and conclusions in this presentation have not been formally disseminated by the U.S. Environmental Protection Agency and should not be construed to represent any Agency determination of policy.

Breast cancer among Alaska Native women potentially exposed to environmental organochlorine chemicals

Objectives. To determine if an increased rate of breast cancer in Alaska Native women is related to their consumption of a subsistence diet that may contain p, p’-dichlorodiphenylethylene (DDE) and polychlorinated biphenyls (PCBs).Study Design. A retrospective case control design.Methods. We analyzed banked serum collected between 1981 and 1987 from 126 Alaska Native women, including 63 case women who subsequently developed breast cancer and 63 age-matched control women who remained cancer-free. Serum was analyzed for DDT, DDE, 13 other chlorinated pesticides, and 28 PCB congeners.Results. The geometric mean for p, p’-DDE levels among case women was 8.67 ppb (95% Confidence Interval 7.48, 10.04); among control women, the geometric mean was 7.36 ppb (6.53, 8.30). The geometric mean for total PCB levels among case women was 4.55 ppb (3.61, 5.74) and for control women, the geometric mean was 6.10 ppb (4.73, 7.86). Cancer status and total PCB levels varied across ethnicity (i.e., Eskimo, Aleut, and Indian) but DDE levels were uniform among these ethnic groups. Using conditional logistic regression analysis to adjust for potential confounders (e.g., ethnicity, family history of breast cancer, parity), we found an odds ratio of 1.43 (0.46, 4.47) for the highest tertile of DDE exposure and 0.42 (0.07, 2.38) for the highest tertile of total PCB exposure.Conclusions. Although the results are limited by small sample size and restricted risk factor information, our findings of higher DDE levels, but lower PCB levels among women with breast cancer are consistent with previous research. Our results confirm exposure to organochlorines among Alaska Native women but do not identify these exposures as a significant risk factor for breast cancer.

Exposure to 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDT) in relation to bone mineral density and rate of bone loss in menopausal women.

The organochlorine pesticide 2,2-bis(p-chlorophenyl)-1,1,1,-trichloroethane (DDT) and its metabolite 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) are examples of an environmental contaminant that may have hormonal properties. Bone metabolism is both estrogen- and androgen-dependent. Exposures to various environmental endocrine disrupters can affect bone metabolism in animals, but there are no published data concerning the effect of DDE exposure on bone metabolism in humans. We hypothesized that high levels of DDE would be associated with lower bone density in peri- and postmenopausal women than in premenopausal women. Study subjects were drawn from the cohort of women who had participated in the Mount Sinai Medical Center Longitudinal Normative Bone Density Study (1984-1987). We used serum samples obtained at study entry to measure DDE levels in 103 (50 black, 53 white) women (mean age = 54.5 y [standard deviation = 5 y]). Measurements of bone mineral density at the lumbar spine and radius were made at 6-mo intervals during a 2-y period. DDE concentrations were significantly (p < .001) higher in blacks (13.9 ng/ml) than in whites (8.4 ng/ml), but there was no correlation between DDE concentration and bone density at the spine (mean levels = 1.065 g/cm2 and 1.043 g/cm2 in the lowest and highest quartiles, respectively, of DDE [trend p value = .85]) or at the radius (mean levels = 0.658 g/cm and 0.664 g/cm in the lowest and highest quartiles, respectively, of DDE [trend p value = .34]). Longitudinal analyses revealed no correlation between DDE and the rate of bone loss at either bone site. Similar results were seen in race-stratified analyses, as well as in analyses in which we controlled for lactation history and other potential confounders. We found little evidence that chronic low-level DDT exposure is associated with bone density in peri- and postmenopausal women.

Organochlorine Exposures and Breast Cancer Risk in New York City Women

A hospital-based case-control study of breast cancer risk related to organochlorine (OC) exposure was conducted in a multiethnic setting in New York City. We enrolled 175 breast cancer patients and 355 control patients. The overall racial/ethnic distribution was 57% Caucasian, 21% Hispanic, 22% African-American; cases and controls were frequency-matched by age and race/ethnicity. Tumor markers (estrogen and progesterone receptors, p53, erbB-2) were assessed and organochlorines (DDE, DDT, trans-nonachlor, and higher (HPCB) and lower (LPCB) chlorinated biphenyls) were measured in blood serum. Tumors among minority women were of slightly higher stage than among Caucasians, but tumor markers were similar across the racial/ethnic groups. DDE levels were highest among African-American and Hispanic women; DDT was highest among Hispanics; HPCBs were highest among African-Americans; LPCBs were lowest among Hispanics; and trans-nonachlor was highest among African-Americans. However, OC levels were not associated with risk for breast cancer, nor did OCs differ with respect to tumor stage or tumor markers. Higher DDE levels were associated with increasing body mass index (BMI), but with decreasing level of education, frequency of nulliparity, and frequency of family history of breast cancer. HPCB levels decreased with BMI and were not correlated with breast cancer risk factors. These relationships can be attributed to historical patterns of exposure and to metabolic differences in OCs related to BMI.

Predictors of Plasma Concentrations of DDE and PCBs in a Group of U.S. Women

We evaluated predictors of plasma concentrations of dichlorodiphenyldichloroethylene (DDE), a metabolite of dichlorodiphenyltrichloroethane (DDT), and polychlorinated biphenyls (PCBs) in a group of 240 women, controls from a breast cancer case-control study nested in the Nurses' Health Study. We considered personal attributes such as age, serum cholesterol, region of residence, adiposity, lactation, and dietary intake. DDE levels increased 0.17 ppb/year of age (p = 0.0003), and PCBs increased 0.08 ppb (p = 0.0001). DDE and PCBs increased 0.20 (p = 0.02) and 0.13 ppb (p = 0.001), respectively, per 10 mg/dl serum cholesterol. Women living in the western United States had higher levels of DDE (mean = 11.0 ppb; p = 0.003), and women in the Northeast and Midwest had higher levels of PCBs (mean = 5.6 ppb; p = 0.0002) as compared to women from other parts of the country (mean DDE = 6.3; mean PCBs = 4. 5 ppb). Levels of DDE could not be predicted from consumption of meat, fish, poultry, dairy products, vegetables, fruits, and grains. There was a positive association between fish consumption and PCB concentrations among women in the Northeast and Midwest. Using data from the cases in the nested case-control study to assess the predictive ability of the models, we confirmed that the most reliable predictors of DDE were age and serum cholesterol, and the most important predictors of PCBs were age, serum cholesterol, and residence in the Midwest or Northeast. The null results for the majority of the food variables suggest that specific dietary factors, other than fish, are not currently a substantial contributor to human exposure to DDE and PCBs.

Potential Effects of Environmental Contaminants on Recovery of the Aplomado Falcon in South Texas

Efforts to reintroduce the aplomado falcon (Falco femoralis) into its former range in the southern part of Texas began in 1977. Not until 1993, however, were a significant number (26) of fledgling aplomado falcons released. The first nesting pair of aplomado falcons was reported near the Brownsville Ship Channel during 1995. Because of a long history of pesticide use in the Lower Rio Grande Valley, during 1993-94 we investigated the accumulation of environmental contaminants in plasma of aplomado falcons released at the Laguna Atascosa National Wildlife Refuge. We also assessed the potential contribution of typical prey species to aplomado falcon contaminant burdens. Organochlorine pesticides and PCBs were below detection limits (wet wt basis) in plasma; however, some organochlorines including 1.75 and 1.41 μg/g p,p'-DDE, and 0.49 and 1.52 μg/g total PCBs were detected in addled eggs collected in 1995 and 1996. Mercury also was detected at 1.5 and 4.1 μg/g dry weight in the addled eggs collected in 1995 and 1996. We detected DDE (range 0.02-0.25 μg/g) in carcasses of potential prey of the aplomado falcon. Trace metals also were detected in potential prey at levels which are not of concern, except for Hg, which was high in a few meadowlarks. Low levels of DDE and most trace metals in potential prey, including mourning doves (Zenaida macroura) and eastern meadowlarks (Sturnella magna), are not likely to result in adverse effects on the aplomado falcon in the Lower Rio Grande Valley. However, elevated Hg residues in meadowlarks (in a few cases) and potentially higher DDE levels in other prey species such as the great-tailed grackle (Quiscalus mexicanus) could result in negative effects on reproduction and survival of some aplomado falcons in south Texas.

Long-term trends in organochlorine and mercury residues in some predatory birds in Britain

Residue levels of organochlorine pesticides (HEOD, DDE), polychlorinated biphenyls (PCBs) and mercury (Hg) in the livers of five predatory bird species were monitored in Britain over a 28-year (1963–1990) period. Of two raptor species, sparrowhawks contained higher levels of most chemicals than did kestrels. Among three fish-eaters, herons and kingfishers contained the highest levels of DDE and HEOD, while herons and great-crested grebes contained the highest levels of PCBs and mercury. Species differences were related partly to diet and habitat. In sparrowhawks and kestrels, residues of HEOD and DDE were higher in eastern, arable districts than elsewhere, especially in the 1960s and 1970s. In the fish-eaters, similar regional differences in residue levels were apparent in herons, especially in the 1970s, but not in the other species, for which samples were smaller. Over the 28 years, most species showed significant downward trends in HEOD, DDE and Hg levels, but only two fish-eaters showed significant declines in PCB levels. The downward trends in DDE and HEOD followed successive restrictions in the use of organochlorine pesticides, and were accompanied by recoveries in the populations and breeding success of affected species. Downward trends in mercury were associated with reductions in both agricultural use and industrial emissions.

Organochlorines and mercury in the eggs of British Peregrines Falco peregrinus

The levels of various contaminants were measured in 550 addled and deserted PeregrineFalco peregrinuseggs obtained in Britain during 1963‐86. In this period the population was recovering from a low level imposed by organochlorine pesticides. Over the whole period, HEOD levels declined in eggs from both inland and coastal regions, while DDE levels declined in eggs from inland regions. At the same time, shell‐indices improved. PCB levels increased in eggs from inland regions. At any one time, levels of DDE and HEOD in eggs decreased and shell‐indices increased from south to north within Britain. These gradients fitted with the extent of agricultural land (= pesticide use) and with the extent of Peregrine population decline (both greatest in the south). No south‐north trend was apparent in levels of PCBs derived from industrial sources. In some regions eggs from coastal sites were more contaminated than eggs from inland sites, especially with PCBs and mercury. Significant relationships were found between brood sizes and DDE levels, between brood sizes and shell‐indices, and between shell‐indices and DDE levels. This implied that DDE influenced shell thickness and breeding success. Some evidence was obtained that mercury reduced brood sizes, but no evidence that HEOD and PCB (at the levels found) did so. Overall, DDE and mercury levels together accounted for 17% of the variance in brood sizes during 1963‐86. On a regional basis, DDE had no obvious effect on mean productivity when the geometric mean DDE level in collected eggs was less than 3 p.p.m., and when mean shell‐index was no more than 8% less than normal. At higher DDE levels, and lower shell‐indices, productivity declined markedly. Recovery of regional populations was associated with geometric mean HEOD levels in eggs no greater than 0–7 p.p.m., DDE levels no greater than 15 p.p.m., shell indices no more than about 15–20% below normal, and a mean breeding success exceeding 0–6 young per territorial pair.

Organochlorine residues in human adipose tissue in Spain: Study of an agrarian area

The environmental pollution by persistent organochlorine residues has received much attention in the last years because of its possible effects on wildlife and human health. These residues - organochlorine insecticides, hexa-chlorobenzene (HCB), polychlorinated biphenyls (PCBs) and, in minor levels, polychlorinated dibenzofurans (PCDFs) and dibenzodioxins (PCDDs) - are accumulated in lipid-rich tissues. Their concentrations in adipose tissues of human populations are the best indices in determining the extent of exposure and in evaluating the hazard. In a previous study on the urban population of Barcelona (Spain) during the years 1982-83, high levels of DDE, DDT, /beta/-HCH and HCB were determined. Recently the incidence of HCB in Barcelona has been confirmed by serum determinations. In the present paper the authors have investigated the levels of organochlorine residues - with special concern on HCB- in human adipose tissues from an agrarian area, located at 130 km from Barcelona, mainly devoted to fruit-trees and cereal culture. Results obtained will form part of an up-to-date report on organochlorine pollution in Spain, including several populations of different geographical and socioeconomic characteristics, that will make it possible to identify the sources and trends of this contamination.

Environmental levels ofp,p'‐DDE indicate multiple sources

AbstractStudies undertaken to determine the causes of continuing reproductive failures of populations of peregrine falcons (Falco peregrinus anatum) in Texas and California demonstrate exceptionally high levels of DDE (1,1‐dichloro‐2,2‐bis(p‐chlorophenyl)ethylene) in prey species in western Texas and unchanged high levels of DDE since 1969 in the peregrine population of the central coast of California. Although DDE is a derivative of DDT (p,p'‐DDT; 1,1,1‐trichloro‐2,2‐bis(p‐chlorophenyl)ethane), levels of DDT were very low in in these samples. These observations follow a recent pattern of DDE contamination in the South and Southwest that is characterized by locally high environmental levels of DDE and low levels of DDT. The virtual absence of DDT indicates that the possible illegal uses of DDT, or the transport of DDT compounds from Latin America by migrating birds, cannot account for all of the DDE in these samples. Another source of environmental DDE is therefore indicated.

A note on eggshell porosity, nest humidity and the effects of DDE in the grey heron ( Ardea cinerea)

1. 1. Water vapour conductance ( G H 2O ) was determined for 25 grey heron Ardea cinerea eggs in the laboratory, and in nests during natural incubation at two Scottish colonies. 2. 2. The mean G H 2O of eggs measured in the nest which successfully hatched was 9.0 mgH;O/mmHg/day and the mean water vapour pressure gradient between egg and nest ( ΔP H 2O ), measured using “calibrated” duck eggs, averaged at 31 mmHg (4.13 kPa). 3. 3. Based on eggshell porosity results, from the eggs which hatched, such a gradient would result in a loss of water from the eggs during incubation equivalent to 11% of their fresh weight. 4. 4. Shell thickness, the number of pores/cm 2 of eggshell and DDE content were also determined for the 25 eggs measured in the laboratory. 5. 5. Eggs containing high levels of DDE had thinner shells, more pores in the eggshell and a higher overall eggshell porosity. 6. 6. The main problem posed by a high level of DDE would appear, however, not to be an excessive water loss from the egg during incubation, but rather eggshell thinning leading to a loss of the egg due to breakage in the nest.