Plasma DDE Research Articles

Terrestrial Scavenging of Marine Mammals: Cross-Ecosystem Contaminant Transfer and Potential Risks to Endangered California Condors (Gymnogyps californianus).

The critically endangered California condor (Gymnogyps californianus) has relied intermittently on dead-stranded marine mammals since the Pleistocene, and this food source is considered important for their current recovery. However, contemporary marine mammals contain persistent organic pollutants that could threaten condor health. We used stable carbon and nitrogen isotope, contaminant, and behavioral data in coastal versus noncoastal condors to quantify contaminant transfer from marine mammals and created simulation models to predict the risk of reproductive impairment for condors from exposure to DDE (p,p'-DDE), a major metabolite of the chlorinated pesticide DDT. Coastal condors had higher whole blood isotope values and mean concentrations of contaminants associated with marine mammals, including mercury (whole blood), sum chlorinated pesticides (comprised of ∼95% DDE) (plasma), sum polychlorinated biphenyls (PCBs) (plasma), and sum polybrominated diphenyl ethers (PBDEs) (plasma), 12-100-fold greater than those of noncoastal condors. The mean plasma DDE concentration for coastal condors was 500 ± 670 (standard deviation) (n = 22) versus 24 ± 24 (standard deviation) (n = 8) ng/g of wet weight for noncoastal condors, and simulations predicted ∼40% of breeding-age coastal condors have DDE levels associated with eggshell thinning in other avian species. Our analyses demonstrate potentially harmful levels of marine contaminant transfer to California condors, which could hinder the recovery of this terrestrial species.

Association of type 2 diabetes mellitus with plasma organochlorine compound concentrations.

The increased prevalence of type 2 diabetes mellitus (T2DM) is associated with obesity, age, and sedentary lifestyle, but exposure to some organochlorine (OC) compounds has also been recently implicated. The hypothesis tested is that higher concentrations of bioaccumulative OC compounds are associated with T2DM. Plasma samples were obtained from a cross-section of adult male and female Caucasians and African Americans, either with or without T2DM from two US Air Force medical facilities. A method of extracting OC compounds from human plasma using solid phase extraction was developed, and three OC compounds [p,p'-DDE (DDE), trans-nonachlor, and oxychlordane] were quantified by gas chromatography/mass spectrometry. Multivariable logistic regression modeling indicated that increasing body mass index (BMI) was associated with T2DM in Caucasians but not in African Americans, and African Americans were more likely to have T2DM than Caucasians with decreasing odds ratios as BMI increased. An association between T2DM and increasing plasma DDE (adjusted for age, base, race, and BMI) was observed. Increasing DDE concentrations were associated with T2DM in older individuals and those with lower BMIs. Thus, in this study sample there was a higher risk of T2DM with increasing DDE concentrations in older people of normal weight and relatively lower risk associated with increasing DDE concentrations in those who are overweight or obese.

Concentrations of p,p′-DDE in plasma of nestling Wood Storks from Georgia

We determined the concentrations of organochlorine pesticides and total PCBs in plasma of nestling Wood Storks (Mycteria americana) from two colonies in Georgia in 2000. Of 20 compounds analyzed for, only p,p'-DDE was quantified in reportable concentrations, ranging from <2.0-174.0 ng/g wet weight (ww). Concentrations of p,p'-DDE were significantly greater (P<0.0001) in plasma of nestlings from an inland colony, Chew Mill (x 16.9 ng/g,ww) than a coastal colony, Harris Neck (x 1.2 ng/g,ww). Concentrations from nestlings from Chew Mill were significantly different among sampling weeks (P=0.01), with week 8 being significantly greater than weeks 1, 2, and 5. While the Chew Mill colony had much greater concentrations of p,p'-DDE in plasma of nestlings than the Harris Neck colony, reproduction was greater there (1.8+/-1.0 SD fledged young per nesting attempt) than Harris Neck (1.4+/-1.0 SD fledged young per nesting attempt). While concentrations of p,p'-DDE determined in plasma of nestling Wood Storks are an indirect measure of adult exposure to environmental toxicants, concentrations reported would not be considered detrimental to reproduction in these colonies.

Associations between plasma DDE levels and immunologic measures in African-American farmers in North Carolina.

Experimental studies in rodents demonstrate evidence of immunosuppressive effects of dietary exposure to DDT [2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane], but human data pertaining to immunomodulating effects of DDT exposure are limited. In this study we examined the association between the persistent organochlorine breakdown product 1,1-dichloro-2,2,bis(p-chlorophenyl)ethylene (p,p′-DDE) and immunologic measures using blood samples in a relatively highly exposed population of farmers in the United States. Levels of serum immunoglobulin A (IgA) and IgG and the prevalence of antinuclear antibodies in relation to plasma p,p′-DDE levels were evaluated in samples from 137 African-American male farmers (30–88 years of age; median, 64 years). Participants were recruited through black churches in four rural counties in eastern North Carolina. Data collection included a telephone interview pertaining to farming practices and health history, and one blood sample was collected from each participant. Linear and logistic regression, adjusting for age, cholesterol, triglycerides, smoking status, and years of any kind of pesticide use, was used to assess the association between immunologic parameters and plasma levels of p,p′-DDE. The median plasma p,p′-DDE concentration was 7.7 μg/L (range, 0.6–77.4 μg/L). There was no association between p,p′-DDE and IgA in any of the models. IgG levels decreased with increasing p,p′-DDE levels, with a statistically significant decrease of approximately 50% in the highest two categories of exposure (≥ 6.0 μg/L) compared with values of < 3.0 μg/L. Sixteen (12%) were positive for antinuclear antibodies. The prevalence of antinuclear antibodies was somewhat elevated in the highest category of p,p′-DDE exposure (odds ratio, 1.9; 95% confidence interval, 0.32–11.3; for ≥ 12.0 μg/L compared with < 3.0 μg/L p,p′-DDE), but this difference was not statistically significant. These analyses provide evidence that p,p′-DDE modulates immune responses in humans.

DDT metabolite and androgens in African-American farmers.

The ubiquitous dichlorodiphenyltrichloroethane (DDT) metabolite 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) is an androgen receptor antagonist. Data on potential antiandrogenic activity of DDE in humans are limited. The relations between concentrations of plasma DDE and several serum androgens (total testosterone, bioavailable testosterone, 5alpha-dihydrotestosterone, and free androgen index) were examined in 137 North Carolina black male farmers, using multiple linear regression. Participants ranged in age from 30 to 88 years (mean = 62 years). Most had farmed for about 30 years and 27% reported having used DDT. The median DDE level was 7.7 microg per liter (1213 microg per kg lipid), slightly higher than in other recent studies. Overall, concentrations of DDE and androgens were unrelated. Total testosterone decreased 2% (95% confidence limits [CL] = -9%, 5%) per increase in interquartile distance of lipid-adjusted DDE. The percentage change in other hormones was similarly negligible. However, among those whose DDE level was in the top tenth percentile, compared with all others, total testosterone and free androgen index were lower by 23% (CL= -40%, 1%) and 22% (CL =-41%, 4%) respectively. Plasma androgen levels decreased with age, a relation that has previously been studied only in whites. Studies of more highly exposed populations may be needed to evaluate effects, if any, of DDE.

Plasma 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) levels and immune response.

For determination of whether plasma 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) pesticide levels (< or =1-32 ppb) are associated with immune suppression or DNA damage in lymphocytes, 302 individuals residing in Moore County, North Carolina, in 1994-1996 provided a blood specimen, underwent a skin test, and answered a questionnaire concerning factors affecting plasma organochlorine pesticide levels and the immune system. The blood specimens were analyzed for levels of plasma DDE (a metabolite of 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane), numbers and types of blood cells, immunoglobulin levels, mitogen-induced lymphoproliferative activity, and lymphocyte micronuclei. When DDE levels were categorized as 1 or less, more than 1 to 2, more than 2 to 4.3, more than 4.3 to 7.6, and more than 7.6 ppb, individuals with higher plasma DDE levels had lowered mitogen-induced lymphoproliferative activity (concanavalin A, range: 74,218 dropping to 55,880 counts per minute, p = 0.03) and modestly increased total lymphocytes (range: 2.0-2.3 x 10(3)/microl, p = 0.05) and immunoglobulin A levels (range: 210-252 mg/dl, p = 0.04). There were no consistent differences in response to the skin tests by plasma DDE levels. Plasma DDE levels were not associated with a higher frequency of micronuclei. The authors conclude that relatively low levels of plasma DDE are associated with statistically significant changes in immune markers, although the magnitude of the effects are of uncertain clinical importance.

Effects on the Immune System Associated with Living near a Pesticide Dump Site

In this paper, we report results of the second phase of a larger study designed to evaluate the effects on the immune system of living near a Superfund site containing organochlorine pesticides, volatile organic compounds, and metals. Phase II was conducted to determine whether living near the site, consisting of six locations in Aberdeen, North Carolina, is associated with higher plasma organochlorine levels, immune suppression, or DNA damage. Each of 302 residents of Aberdeen and neighboring communities provided a blood specimen, underwent a skin test, and answered a questionnaire. Blood specimens were analyzed for organochlorine pesticides, immune markers, and micronuclei. Of 20 organochlorines tested, only DDE was detected in the blood of participants (except for one individual). Age-adjusted mean plasma DDE levels were 4.05 ppb for Aberdeen residents and 2.95 ppb (p = 0.01) for residents of neighboring communities. Residents of 40-59 years of age who lived within a mile of any site, but particularly the Farm Chemicals site, had higher plasma DDE levels than residents who lived farther away. Residents who lived near the Farm Chemicals site before versus after 1985 also had higher plasma DDE levels. Overall, there were few differences in immune markers between residents of Aberdeen and the neighboring communities. However, residents who lived closer to the dump sites had statistically significantly lower mitogen-induced lymphoproliferative activity than residents who lived farther away (p &lt; 0.05). Residential location was not consistently associated with frequency of micronuclei or skin test responses. Although some statistically significant differences in immune markers were noted in association with residential location, the magnitude of effects are of uncertain clinical importance.

Effects on the immune system associated with living near a pesticide dump site.

In this paper, we report results of the second phase of a larger study designed to evaluate the effects on the immune system of living near a Superfund site containing organochlorine pesticides, volatile organic compounds, and metals. Phase II was conducted to determine whether living near the site, consisting of six locations in Aberdeen, North Carolina, is associated with higher plasma organochlorine levels, immune suppression, or DNA damage. Each of 302 residents of Aberdeen and neighboring communities provided a blood specimen, underwent a skin test, and answered a questionnaire. Blood specimens were analyzed for organochlorine pesticides, immune markers, and micronuclei. Of 20 organochlorines tested, only DDE was detected in the blood of participants (except for one individual). Age-adjusted mean plasma DDE levels were 4.05 ppb for Aberdeen residents and 2.95 ppb (p = 0.01) for residents of neighboring communities. Residents of 40-59 years of age who lived within a mile of any site, but particularly the Farm Chemicals site, had higher plasma DDE levels than residents who lived farther away. Residents who lived near the Farm Chemicals site before versus after 1985 also had higher plasma DDE levels. Overall, there were few differences in immune markers between residents of Aberdeen and the neighboring communities. However, residents who lived closer to the dump sites had statistically significantly lower mitogen-induced lymphoproliferative activity than residents who lived farther away (p < 0.05). Residential location was not consistently associated with frequency of micronuclei or skin test responses. Although some statistically significant differences in immune markers were noted in association with residential location, the magnitude of effects are of uncertain clinical importance.

Gender differences in response to the Multitest CMI skin test in the general population

Previous studies of gender differences in response to the Multitest CMI skin test have produced conflicting results. To determine whether gender is associated with response to the Multitest CMI skin test. Two-hundred ninety-seven adults, aged 18 to 64 years, recruited originally for a study of the immune effects associated with living near a hazardous waste site containing primarily organochlorine pesticides, underwent a skin test using the Multitest CMI skin test. Six of seven antigens were tested: tetanus toxoid, diphtheria toxoid, Candida, Tricophyton, Streptococcus, and Proteus. The tuberculin antigen was excluded. Lymphocyte function was also evaluated in vitro using standardized methods of mitogen stimulation with phytohemaglutinin (PHA), concanavalin A (CON-A), and pokeweed mitogen. The frequency of positive responses to the skin tests was significantly (P < .001) higher among males (80.4%) than among females (55.7%). Males were more likely than females to respond to all six antigens tested (P < .05). The mean diameter of positive skin test measurements for males statistically significantly (P < .05) exceeded female responses for tetanus and diphtheria. Although not statistically significant, male response size exceeded that of females for all other antigens except Trycophyton. Controlling for age, race, smoking, income, and plasma DDE levels did not change these results. Skin test positivity was not associated with mitogen stimulation assay results overall or within gender groups. Significant gender differences in response to the Multitest CMI skin test could limit its use as a marker of anergy in general population studies.

Fish Consumption and Contaminant Exposure among Montreal-Area Sportfishers: Pilot Study

A 1995 pilot study assessed sport fish consumption and contaminant exposure among Montreal-area residents fishing the frozen St. Lawrence River. Interviews conducted among 223 ice fishers met on-site were used to create an index of estimated exposure to fish-borne contaminants. A second-stage assessment of sport fish consumption and tissue contaminant burdens included 25 interviewees at the highest level of estimated contaminant exposure (of 38, or 66% of those solicited) and 15 low-exposure fishers (of 41, or 37% of those solicited). High-level fisher–consumers reported eating 0.92±0.99 sport fish meals/week during the previous 3 weeks compared to 0.38±0.21 (P<0.05) for the low-level group. Based on the product of consumption frequency times mass of sport fish meals consumed, high-level consumers ate a mean of 18.3 kg of sport fish annually versus 3.3 kg for the low-level consumers. Tissue contaminant assessments showed significant (P<0.05) groupwise differences: 0–1 cm hair mercury (median 0.73 μg/g for the high versus 0.23 μg/g for the low group), lipid-adjusted plasma PCB congeners (Aroclor 1260: median 0.77 μg/g versus 0.47μg/g), and lipid-adjusted plasma DDE (median 0.35 μg/g versus 0.26 μg/g). No participant had a hair mercury or plasma DDE concentration above Health Canada recommendations but 2/25 high-level participants (8%) had plasma Aroclor 1260 concentrations above recommended limits. The results of this pilot study suggest that a small number of Montreal-area sportfishers consume their catch as often as three times weekly and that those consuming sport fish frequently have significantly higher tissue levels of mercury, PCBs, and DDE than do infrequent consumers. On the other hand, compared to other groups in Quebec, such as the Inuit or commercial fishers on the North Shore of the Gulf of St. Lawrence, Montreal-area sportfishers eat less fish and have lower tissue concentrations of fish-related contaminants.

Chlorinated hydrocarbon contaminants and productivity of bald eagle populations on the Pacific coast of Canada

AbstractFrom 1991 to 1995, we studied bald eagle populations breeding near three pulp mills in the Strait of Georgia, in the Fraser River estuary, and at remote reference sites on the west coast of Vancouver Island, northern Johnstone Strait, and the Queen Charlotte Islands (Haida Gwaii). Our objective was to determine occupancy of breeding territories, measure nest success, and compare the results to chlorinated hydrocarbon levels in eggs and in nestling plasma samples. Blood samples were collected in 1993 and 1994 from 52 nestlings in 38 nests and plasma analyzed for polychlorinated dibenzo‐p‐dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), organochlorine (OC), pesticides, and lipid content. Most measured compounds partitioned with plasma lipids, with the exception of hepta‐ and octachlorinated dioxins and furans. Because of significant variation in plasma lipid content among sites, contaminant concentrations were adjusted using analysis of covariance (ANCOVA). Mean concentrations of 2,3,7,8‐substituted PCDDs, PCDFs, and calculated international toxic equivalents (I‐TEQs) in nestling plasma were highest in samples from near pulp mills on southeast Vancouver Island (Nanaimo and Crofton) and Powell River. Mean total PCB concentrations were also highest in the industrialized Strait of Georgia region, such as at Powell River (56 μg/kg), while OC pesticide concentrations, including 1,1‐dichloroethylene bis(p‐chlorophenyl) (DDE), did not vary significantly among sites. Nest success was followed for 5 years at 250 breeding territories in the nine study areas. Average productivity was higher at most study sites around the Strait of Georgia compared to the reference areas. There were no significant relationships between productivity and I‐TEQs or any tetrachlorodibenzo‐p‐dioxin‐like compounds for the whole data set; only DDE in plasma was weakly related to productivity. Likewise, there were no significant relationships between individual nest productivity and contaminant levels in eggs, based on previously published data. We also tested for variability within study areas by comparing productivity at nests adjacent to dioxin fishery closure areas at three pulp mills compared to nearby nests outside the closure areas. At two pulp mill sites, Powell River and Nanaimo, there were no differences in productivity; however, at Crofton, average productivity, 0.26 young/occupied territory, was significantly lower at nine bald eagle territories adjacent to a dioxin—fishery closure zone compared to eight territories outside of the closure area, 1.0 young/occupied territory. The cause of the low reproductive rate at Crofton has not been determined, although a toxicological explanation has not been ruled out.

Internal exposure to hazardous substances of persons from various continents: investigations on exposure to different organochlorine compounds.

The aim of the study was to investigate the concentration of organochlorine compounds of environmental-medical relevance in biological materials from refugees with regard to their countries of origin and to compare these concentrations with the internal exposure of the German general population. During medical examination after entry to Germany specimens could be taken from the refugees to determine the following parameters of biological monitoring: 1,1-dichloro-2,2-bis(-chlorophenyl)-ethylene (DDE-P), polychlorinated biphenyls (PCB-P), pentachlorophenol (PCP-P) and the beta- and gamma-hexachlorocyclohexanes (beta-HCH-P, gamma-HCH-P) in plasma and the excretion of chlorophenols (4-MCP-U, 2,4-DCP-U, 2,5-DCP-U, 2,4,5-TCP-U, 2,4,6-TCP-U, 2,3,4,5-TeCP-U, 2,3,5,6-TeCP-U) in urine. One hundred and three men (13 from former Yugoslavia, 29 from the former USSR, 33 Africans and 28 Asians) ranging from 16 to 53 years of age (median 27 years) were investigated. Thirty four male Germans without occupational exposure to these substances and a similar age structure (age 25-36 years; median 26 years) served as a control group. A much higher level of internal exposure was found for the DDT metabolite, DDE, for those persons from Asia, the former USSR and Africa compared with the German controls (medians: 16.9 micrograms/l, 11.9 micrograms/l and 10.9 micrograms/l) and 1.1 micrograms/l). The levels of PCB in plasma were below the detection limit in the majority of refugees. In the control group, however, the PCB levels were higher (sigma PCB; median: 2.1 micrograms/l, maximum: 13.3 micrograms/l). The highest beta-HCH concentrations, up to a maximum of 15.5 micrograms/l, were detected in the persons from the former USSR and Asia. The five groups do not differ with regard to internal exposure to PCP and gamma-HCH. Renal excretion of 4-MCP, 2,4-DCP and TeCP did not differ between the five groups. The concentrations of 2,5-DCP in urine, however, were significantly lower in the Germans than the refugees from the four regions investigated. The median for the Germans was 3.0 micrograms/l and for the refugees between 10.8 and 14.7 micrograms/l. Also the levels of 2,4,5-TCP and 2,4,6-TCP in urine were lower in the German controls than in the men from the former USSR, Africa and Asia. Organochlorine compounds exist worldwide due to their extensive use. There are, however, regional differences for the various substance groups, which during biological monitoring are seen in the different background exposures of the general population. Particularly characteristic are markedly higher levels of DDE in plasma from the refugees compared with the German population.

Concentration of DDT and DDE in plasma and subcutaneous adipose tissue before and after intestinal bypass operation for treatment of obesity

DDT and its principal metabolite, DDE, are stored mainly in body fat. In spite of a general prohibition in household use in 1970, the general population in Sweden is still exposed to these pesticides in the diet. The aim of this study was to examine whether weight loss is followed by increased concentrations of the pesticides in adipose tissue and plasma and whether increased concentrations could possibly explain some unusual neurological symptoms observed in some patients after a shunt operation. Eight subjects were examined before and 1 year after jejuno-ileostomy. The mean weight loss was 46.9 ± 2.8 kg ( X + SE ). The concentrations of p, p′-DDE in plasma increased significantly from 5.1 ± 0.9 to 8.2 ± 1.3 ng/ml during the weight loss. This concentration is still well below the concentration in a control group of nonexposed office personnel whose mean concentration is 19 ± 4.0 ng/ml. In adipose tissue the mean concentrations of p, p′-DDT and p, p′-DDE increased from 390 ± 65 to 526 ± 107 ng/g and 863 ± 136 to 1341 ± 194 ng/g, respectively. The ratio of DDE: DDT increased in all but one subject, indicating an increased metabolism of DDT after the operation. The calculated total body content of DDT and DDE decreased in all but two patients after the bypass operation due to increased metabolism and excretion. The risk of DDT intoxication following an intestinal bypass operation appears to be small.