Obesity and persistent organic pollutants: possible obesogenic effect of organochlorine pesticides and polychlorinated biphenyls

Persistent organic pollutants (POPs) are endocrine-disrupting chemicals associated with the development of the metabolic syndrome and type 2 diabetes. In humans, little is known about their role in the potential origin of obesity. This study aims to assess the associations between serum levels of POPs and the prevalence of obesity in a cohort of obese and lean adult men and women. POP serum samples were investigated cross-sectionally in 98 obese and 47 lean participants, aged ≥18 years. Serum samples were analyzed for the presence of polychlorinated biphenyl (PCB) congeners 153, 138, 180, and 170 and for the organochlorine pesticides, dichloro-diphenyl-dichloroethylene (pp-DDE), and β-hexachlorocyclohexane (βHCH). We established a significant negative correlation between BMI, waist, fat mass percentage, total and subcutaneous abdominal adipose tissue, and serum levels of PCB 153, 180, 170, and the sumPCBs. For βHCH, we demonstrated a positive correlation with BMI, waist, fat mass percentage, and total and subcutaneous abdominal adipose tissue. PCBs 180, 170, and the sum of PCBs correlated significantly negative with homeostasis model assessment for insulin resistance (HOMA(IR)). βHCH correlated significantly positively with HOMA(IR). A strong correlation was established between all POP serum levels and age. We established a positive relationship between high serum levels of βHCH and BMI and HOMA(IR), whereas serum PCB levels were inversely correlated with BMI and HOMA(IR). Combined, these results suggest that the diabetogenic effect of low-dose exposure to POPs might be more complicated than a simple obesogenic effect.

Organochlorine pesticide gradient levels among maternal adipose tissue, maternal blood serum and umbilical blood serum

The objective of the present study was to determine levels and calculate ratios of copartition coefficients among organochlorine pesticides β-HCH, pp'DDE, op'DDT and pp'DDT in maternal adipose tissue, maternal blood serum and umbilical blood serum of mother-infant pairs from Veracruz, Mexico. Organochlorine pesticides were analyzed in 70 binomials: maternal adipose tissue, maternal serum and umbilical cord serum samples, using gas chromatography with electron capture detection (GC-ECD). The results were expressed as mg/kg on fat basis. p,p'-DDE was the major organochlorine component, detected in every maternal adipose tissue (0.770 mg/kg), maternal serum sample (5.8 mg/kg on fat basis) and umbilical cord blood sample (6.9 mg/kg on fat basis). p,p'-DDT was detected at 0.101 mg/kg, 2.2 mg/kg and 5.9 mg/kg respectively, according to the order given above. β-HCH was detected at 0.027 mg/kg, 4.2 mg/kg and 28.0 mg/kg respectively. op'DDT was detected only in maternal adipose tissue at 0.011 mg/kg. The copartition coefficients among samples identify significant increases in concentrations from adipose tissue to maternal blood serum and to umbilical blood serum. The increase indicated that maternal adipose tissue released organochlorine pesticides to blood serum and that they are carried over to umbilical cord blood.

Increased risk of non-Hodgkin lymphoma and serum organochlorine concentrations among neighbors of a municipal solid waste incinerator

Organochlorine chemicals may contribute to an increased risk of non-Hodgkin lymphoma (NHL) within non-occupationally exposed populations. Among these chemicals, dioxins and furans were mainly released by municipal solid waste incinerators (MSWIs) until a recent past in France, a source of exposure that is of public concern. We investigated organochlorines and the risk of NHL among neighbors of a French MSWI with high levels of dioxin emissions (Besançon, France), using serum concentrations to assess exposure. The study area consisted of three electoral wards, containing or surrounding the MSWI. Pesticides, dioxins, furans, and polychlorinated biphenyls (PCBs) were measured in the serum of 34 newly diagnosed NHL cases (2003-2005) and 34 controls. Risks of NHL associated with each lipid-corrected serum concentration were estimated using exact logistic regression. The pesticides β-hexachlorocyclohexane (odds ratio [OR]=1.05, 95% confidence interval [CI]=1.00-1.12, per 10 ng/g lipid) and p,p' dichloro-diphenyl-trichloroethane (DDT) (OR=1.20, 95% CI=1.01-1.45, per 10 ng/g lipid) were associated with NHL risk. Evidence indicated an increased NHL risk associated with cumulative WHO(1998)-toxic equivalency factor (TEQ) concentrations (dioxins, OR=1.12, 95% CI=1.03-1.26; furans, OR=1.16, 95% CI=1.03-1.35; dioxin-like PCBs, OR=1.04, 95% CI=1.00-1.07; and total TEQ, OR=1.04, 95% CI=1.01-1.05), as well as with non dioxin-like PCBs (OR=1.02, 95% CI=1.01-1.05, per 10 ng/g lipid). Most congener-specific associations were statistically significant. This study provides strong and consistent support for an association between serum cumulative WHO(1998)-TEQ concentrations, at levels experienced by people residing in the vicinity of a polluting MSWI, and risk of NHL.

Distribution of persistent organochlorine chemical residues in blood plasma of three species of vultures from India

The presence of persistent organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in blood plasma of white-backed vulture Gyps bengalensis, Egyptian vulture Neophron percnopterus, and griffon vulture Gyps fulvus collected from Ahmedabad, India. All the samples had varying levels of organochlorine pesticides and PCBs. Statistically significant (P<0.05) differences among species were detected for beta-hexachlorocyclohexane (β-HCH), ∑HCH, and dichloro-diphenyl-trichloroethane (DDT). The mean concentration of ∑HCH, ∑DDT, and ∑PCBs among plasma ranged from 43.7 to 136, 8.8 to 64.8, and 226 to 585 ng/ml, respectively. Among the various OCPs analyzed, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE) was detected most frequently. The concentrations of cyclodiene insecticides detected were lower than the other organochlorine residues. The levels of pesticides measured in plasma samples of three species of vulture were comparable to the results documented for a number of avian species and were lower than those reported to have deleterious effects on survival or reproduction of birds. Although no threat is posed by any of the organochlorine pesticides detected, continuous monitoring of breeding colonies is recommended. This study is also the first account of a comprehensive analysis of toxicants present in blood plasma of vulture species in India. The values reported in this study can serve as guidelines for future research in general as well as control values during the analysis of samples obtained from birds in the event of suspected organochlorine poisoning.

Prenatal exposure to organochlorine compounds and neonatal thyroid stimulating hormone levels

It has been suggested that prenatal exposure to some organochlorine compounds (OCs) may adversely affect thyroid function and may, therefore, impair neurodevelopment. The main aim of this study was to examine the relationship of cord serum levels of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4'-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4'-DDE), β-hexachlorocyclohexane (β-HCH), hexachlorobenzene (HCB), four individual polychlorobiphenyl (PCB) congeners (118, 138, 153, and 180), and their sum, with neonatal thyroid stimulating hormone (TSH) levels in blood samples in a mother-infant cohort in Valencia, Spain. This study included 453 infants born between 2004 and 2006. We measured OC concentrations in umbilical cord serum and TSH in blood of newborns shortly after birth. Associations between neonatal TSH levels and prenatal OC exposure adjusted for covariates were assessed using multivariate linear regression analyses. Neonatal TSH levels tended to be higher in newborns with β-HCH levels in umbilical cord above 90th percentile (104 ng/g lipid) than in those with levels below the median (34 ng/g lipid), with an adjusted increment in neonatal TSH levels of 21% (95% confidence interval=-3, 51; P=0.09). No statistically significant association was found between the remaining OCs and TSH at birth. Prenatal exposure to β-HCH may affect neonatal thyroid hormone status and its function in neurological development.

Concentrations and determinants of organochlorine levels among pregnant women in Eastern Spain

Persistent organic pollutants (POPs) comprise a large variety of toxic substances with ample distribution. While exposure to these toxins occurs mainly through diet, maternal POP levels may be influenced by certain sociodemographic, environmental, or lifestyle factors. This is important given that these substances may have adverse effects on fetal development. The aim of this study is to examine the sociodemographic, environmental, lifestyle, and dietary determinants of the levels of hexachlorobenzene (HCB), b-hexachlorocyclohexane (b-HCH), 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4'-DDT), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (4,4'-DDE), and polychlorinated biphenyls (PCB congeners 118, 138, 153, 180) measured in the blood of pregnant women participating in a mother-child cohort study conducted in Valencia (Spain). The study population consisted of 541 pregnant women who formed part of the INMA (Childhood and the Environment) cohort (2004-2006). POP levels were determined in blood taken during the 12th week of pregnancy with the aid of gas chromatography with electron capture detection. Sociodemographic, environmental, and dietary information was obtained from a questionnaire. Multivariate Tobit regression models were constructed in order to assess the association between POP levels and selected covariates. The results showed that all the women had detectable levels of at least one of these compounds while in 43% of the subjects, all eight compounds were detected. The compounds found in the greatest number of women were 4,4'-DDE (100%) and PCBs 153 and 180 (95%). The most important determinants of high POP levels were the mother's age, country of origin, increased body mass index, and number of weeks of breastfeeding after previous pregnancies. With regard to diet, 4,4'-DDT and 4,4'-DDE levels increased with the intake of meat, fruit, and cereal. PCB 153 levels increased with the intake of seafood. The levels of HCB, b-HCH, 4,4'-DDT, and 4,4'-DDE observed in this study were slightly higher than in other studies, whereas the PCB levels were similar.

A screening of persistent organohalogenated contaminants in hair of East Greenland polar bears

In this pilot study, we report on levels of persistent organohalogenated contaminants (OHCs) in hair of polar bears (Ursus maritimus) from East Greenland sampled between 1999 and 2001. To our knowledge, this is the first study on the validation of polar bear hair as a non-invasive matrix representative of concentrations and profiles in internal organs and blood plasma. Because of low sample weights (13-140mg), only major bioaccumulative OHCs were detected above the limit of quantification: five polychlorinated biphenyl (PCB) congeners (CB 99, 138, 153, 170 and 180), one polybrominated diphenyl ether (PBDE) congener (BDE 47), oxychlordane, trans-nonachlor and β-hexachlorocyclohexane. The PCB profile in hair was similar to that of internal tissues (i.e. adipose, liver, brain and blood), with CB 153 and 180 as the major congeners in all matrices. A gender difference was found for concentrations in hair relative to concentrations in internal tissues. Females (n=6) were found to display negative correlations, while males (n=5) showed positive correlations, although p-values were not found significant. These negative correlations in females may reflect seasonal OHC mobilisation from periphery adipose tissue due to, for example, lactation and fasting. The lack of significance in most correlations may be due to small sample sizes and seasonal variability of concentrations in soft tissues. Further research with larger sample weights and sizes is therefore necessary to draw more definitive conclusions on the usefulness of hair for biomonitoring OHCs in polar bears and other fur mammals.

Organochlorine pesticide levels in umbilical cord blood of newborn in Veracruz, Mexico

Organochlorine pesticides accumulate in lipid rich compartments of organisms. During pregnancy, the compounds pass through the placental barrier appear in cord blood. The aim of this study was to monitor the levels of organochlorine pesticides in 70 umbilical cord blood samples taken during deliveries in Veracruz in 2009. For organochlorine pesticides, only the presence β-HCH (4%, 3.9 μg/L median concentration on wet weight), pp'DDE (100%, 0.7 μg/L) and pp'DDT (4%, 1.4 μg/L) were detected. The total pool of samples divided according to sex of new born babies, showed no statistical differences among median concentrations. The number of deliveries considered as a determinant contamination factor affirmed there were no statistical differences among median concentrations; however pp'DDE levels increased from the one to two childbirth groups. Age of pregnant women as a discriminate factor manifests in a significant increase in contamination levels among first, second and third tertile. In general, umbilical cord blood samples in Veracruz contained organochlorine pesticides, especially pp'DDE, confirming the presence of these compounds in the environment and their transfer from the mother to the developing fetus.

Exposure to persistent organic pollutants (POPs) and DNA damage as an indicator of environmental stress in fish of different feeding habits of Coatzacoalcos, Veracruz, Mexico

The region of Coatzacoalcos, Veracruz hosts one of the largest and most important industrial areas of Mexico and Latin America. Industrial development and rapid population growth, have triggered a severe impact on aquatic ecosystems of the region. The aim of this study was to determine the levels of POPs in sediment and in muscle tissue of five fish species from different trophic levels in downstream residents of the Coatzacoalcos River, and their integration with DNA damage in the fish, evaluated with the comet assay in whole blood as a biological indicator of stress, in order to obtain a baseline of the ecological condition of the region. The compounds detected in sediment and in muscle tissue were hexachlorobenzene (HCB), α-, β-, γ-hexachlorocyclohexane (HCH), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE), mirex and polychlorinated biphenyls (PCBs). Sediment concentrations of these pollutants (except for mirex) exceeded the values of protection provided by international guidelines, suggesting a potential risk to aquatic life in the region. DNA damage recorded in the fish species is evidence of exposure to a mix of genotoxic pollutants, which combined with exposure to POPs, reflects the degree of environmental stress of aquatic organisms in the region. The results of this study show the importance of determining the presence of contaminants in the environment, the bioaccumulation in tissues and their effects on exposed organisms, providing an integrated approach in assessing the health of aquatic ecosystems.

Human exposure to persistent organic pollutants in West Africa--a temporal trend study from Guinea-Bissau

BACKGROUND

Humans, independent on where they live, are exposed to complex and various mixtures of chemicals, including persistent organic pollutants (POPs). The variability of the exposure depends on sources of the chemicals and is influenced by e.g. geography, social and cultural heritage. While exposures to POPs are frequently studied in populations from developed industrial countries, very little is known on levels and trends of POPs in developing countries, especially in Africa.

OBJECTIVES

The aim of the present study was to investigate levels and temporal trends of POPs in adults from Guinea-Bissau.

METHODS

Serum samples were obtained from an open cohort of police officers in Guinea-Bissau. Repeated samples from 33 individuals were obtained at five time points between 1990 and 2007, in all 147 samples. Pooled serum samples were extracted and cleaned-up prior to analysis by gas chromatography and mass spectrometry. The concentration of 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (4,4'-DDT) and its metabolites, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexachlorocyclohexanes (HCHs) were determined.

RESULTS

The major POP found in all samples was 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (4,4'-DDE) followed by 4,4'-DDT. 4,4'-DDE, 4,4'-DDT, PCBs and beta- and gamma-HCH were significantly decreasing over time. The PBDEs were found at low concentrations, with an increasing temporal trend for BDE-153.

CONCLUSION

National and international management may be behind the observed decreased organohalogen compound concentrations in humans from Guinea-Bissau from the early 1990's and onwards, similarly to the development of these compounds in humans from industrial countries. In contrast, PBDEs follow a trend of increasing concentrations even though at low levels.

Concentrations of selected organochlorines and chlorobenzenes in the serum of former Love Canal residents, Niagara Falls, New York

BACKGROUND

Love Canal, in Niagara Falls, NY is among the earliest and most significant hazardous waste sites in the USA, but no study has ever measured chemical body burdens in nearby residents to document that human exposure occurred. This study measured concentrations of selected organochlorines and chlorinated benzenes in archived serum samples collected from former Love Canal residents.

METHODS

We analyzed serum samples collected from 373 former residents in 1978-1979 for compounds disposed of at Love Canal, and we compared their concentrations according to surrogate indicators of exposure such as residential proximity, adjusting for potential confounders.

RESULTS

Three compounds were detectable in the serum of most participants: 1,2,4-trichlorobenzene (1,2,4-TCB), beta-hexachlorocyclohexane (beta-HCH) and 1,2-dichlorobenzene (1,2-DCB). Concentrations of 1,2,4-TCB and 1,2-DCB were 2-14 times greater among persons who at the time their blood was collected lived closest to the Canal compared to those living further away. We found no consistent trends for beta-HCH with respect to any exposure definition.

CONCLUSIONS

These results provide evidence that residential proximity to Love Canal contributed to the body burden of certain contaminants, and helps validate the use of surrogate exposure measures in health effect studies. Further surveillance of the Love Canal cohort is warranted.

Enantioselective behavior of alpha-HCH in mouse and quail tissues

alpha-HCH (hexachlorocyclohexane) is chiral and can still be detected in almost all environmental media. In this study, the enantioselective behavior of alpha-HCH in mice (CD1) and quail (Coturnix japonica) was investigated and compared after a single dose of exposure. The primary nerve cell culture was conducted to evaluate the enantioselective metabolic capacity of nerve cells of mouse and quail for alpha-HCH. In various tissues of the mice and quail, the alpha-HCH concentrations showed a typical pattern of first-order dynamics after exposure. The enantiomeric fractions (EFs) in nonbrain tissues of mice decreased substantially, indicating continuous depletion of (+)-alpha-HCH in mice. Tissue-specific EF trends in quail and enantioselective degradation of (-)-alpha-HCH in quail liver were observed. These observations indicated that the dynamic changes of EFs in mice and quail were independent of concentration changes in the same tissues. In brain tissues, the enantioenrichment of (+)-enantiomer was totally independent of their concentrations in blood. The in vitro metabolism of alpha-HCH in the primary nerve cells were negligible, and the slight EF changes in primary nerve cells demonstrated that metabolism, uptake, and excretion in the brain cells would not lead to the observed dramatic enantioenrichment of (+)-alpha-HCH in the brain tissues of the two animals. The enantioselective transport across the blood-brain barrier was the primary cause for the enantioenrichment of (+)-alpha-HCH in the brain tissues.

Associations of serum concentrations of organochlorine pesticides with breast cancer and prostate cancer in U.S. adults

BACKGROUND

Organochlorine (OC) pesticides are a group of environmental endocrine disruptors that may be associated with an increased risk for hormone-related cancers including cancers of the breast and prostate. However, epidemiologic evidence is limited and inconsistent.

OBJECTIVES AND METHODS

We used 1999-2004 National Health and Nutrition Examination Survey data to examine associations between serum concentrations of OC pesticides and prostate and breast cancers.

RESULTS

After adjustment for other covariates, serum concentrations of beta-hexachlorocyclohexane (HCH) (p for trend = 0.02), trans-nonachlor (p for trend = 0.002), and dieldrin (p for trend = 0.04) were significantly associated with the risk of prevalent prostate cancer. Adjusted odds ratios for the second and third tertiles of detectable values were 1.46 [95% confidence interval (CI), 0.52-4.13] and 3.36 (95% CI, 1.24-9.10) for beta-HCH; 5.84 (95% CI, 1.06-32.2) and 14.1 (95% CI, 2.55-77.9) for trans-nonachlor; and 1.06 (95% CI, 0.30-3.73) and 2.74 (95% CI, 1.01-7.49) for dieldrin compared with concentrations in the lowest tertile or below the limit of detection. However, there was no positive association between serum concentrations of OC pesticides and breast cancer prevalence.

CONCLUSION

Although further study is necessary to confirm these findings, these results suggest that OC pesticide exposures may have a significant effect on cancer risk. Efforts to reduce worldwide OC use are warranted.

Correcting serum concentrations of organochlorine compounds by lipids: alternatives to the organochlorine/total lipids ratio

INTRODUCTION

When studying the effects of organochlorine compounds (OCs) on human health it is common to correct serum concentrations of OC by total lipids (TL). However, the relationship between serum OCs and serum TL is far from established in many diseases, including several cancers. Our aim was to analyze the relationship between serum OC and TL in patients with pancreatic ductal adenocarcinoma (PDA), and to explore several alternatives to perform the OC lipid correction.

METHODS

Incident cases of PDA were interviewed and had blood drawn soon around hospital admission (n=144). Serum concentrations of OCs were analysed by high-resolution gas chromatography with electron-capture detection.

RESULTS

Most patients with high TL had moderate or low concentrations of OCs. By contrast, the variability of OC values among patients with normal TL was large. Correlations were of a similar magnitude between OC and TL and between OC and total cholesterol; while these correlations were weak (all Spearman's rho<0.3 and R(2)<0.11), no OC were significantly correlated with triglycerides. Although all alternatives to the OC/TL linear ratio were statistically significant for at least one OC, their R(2) was always below 10%.

CONCLUSIONS

In patients with severe diseases as PDA, linear correction of OC by TL as commonly performed in epidemiologic studies may be inappropriate. Results contribute to the scant literature on the rationale to correct serum concentrations of OC by lipids. They suggest that it is unwarranted to routinely correct OC by TL, offer ways to assess such need, and present alternatives as no TL correction, correction by total cholesterol only or use of different statistical models.

Combining data sets of organochlorines (OCs) in human plasma for the Russian Arctic

As part of AMAP's human circumpolar study of POPs, an international effort was initiated to extend coverage to communities across the Russian Arctic. Two additional laboratories were invited to join the analytical component of this effort, resulting in four participating analytical centres. Although quality assurance measures were put in place, and the level of performance of the laboratories was generally acceptable, deficiencies in the analytical protocols used were recognized subsequent to the collection and analyses of the plasma specimens. The current paper describes the criteria employed to critically appraise the four data bases and guide their integration into a single data set. Summary statistics are presented for plasma concentrations of major PCBs, p,p'-DDE, p,p'-DDT, beta-HCH, and HCB for communities/regions across the arctic/subarctic Russian continent, and for one community located in the Aral Sea area of Uzbekistan (a control group). Highly exposed people were identified in the coastal communities of Chukotka, which appears mainly related to marine mammal intake, but recent pesticide use is also suspected. Other communities with intermediate levels of PCBs had relatively elevated beta-HCH, p,p'-DDT and HCB concentrations and low DDE/DDT ratios (<10), suggesting recent pesticide use.

Serum levels of organochlorine pesticides in healthy adults from five regions of Spain

The aim of this study was to measure of serum levels of p,p'-dichlorodiphenyl trichloroethane (p,p'-DDT), p,p'-dichlorodiphenyl dichlorethylene (p,p'-DDE), beta-hexachlorocyclohexane (beta-HCH), and hexachlorobenzene (HCB) in healthy adults in Spain. Furthermore, we also analyzed these levels according to dietary, other lifestyle factors and anthropometric characteristics. We measured the concentrations of such organochlorine pesticides (OCPs) in serum samples collected during 1992-1996 from 953 subjects aged 35-64 years, they were residents of five Spanish regions, they were randomly selected from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. OCPs were determined by means of gas chromatography with electron-capture detection (GC-ECD). The most frequent compound found in serum was p,p'-DDE, present in 98% of the samples, followed by HCB and beta-HCH, found in 89% and 77% of samples, respectively, while p,p'-DDT could be measured only in 26% of subjects. The geometric means of serum concentrations (ng/g lipid) were 822 for p,p'-DDE, 167 for beta-HCH, and 379 for HCB. The concentrations of all OCPs were positively associated with age and body mass index, and decreased along the period of blood collection. No association was found between OCPs levels and dietary factors. The concentrations of p,p'-DDE and beta-HCB were higher in Murcia, one of southern regions, most likely associated with intensive past use of pesticides related to agricultural practices, while higher levels of HCB were found in Navarra, located in the north, maybe due to industrial use rather than agricultural application.

[A case-control study on serum organochlorines residues, genetic polymorphisms of glutathione S-transferase T1 and the risks of breast cancer]

OBJECTIVE

To study the potential effect of gene-environment interaction between glutathione S-transferase T1 (GSTT1) and serum organochlorines residues on the risk of breast cancer in women, in China.

METHODS

70 newly diagnosed female breast cancer patients and 30 controls from September 2006 to October 2007 were interviewed using the same questionnaire to obtain information regarding exposure to those risks. Organochlorine residues level in serum was measured by gas chromatography (GC). Genotypes of GSTT1 polymorphisms were analyzed by multiplex allele-specific polymerase chain reaction (PCR). Interaction indexes (gamma) were calculated to determine the type of gene-environment interaction.

RESULTS

After adjusting the confounding factors, results showed that interaction existed in genetic polymorphisms of GSTT1 and dichlorodiphenyltrichloroethane (DDT)/hexachlorocyclohexane (HCH) residues, with interaction indexes (gamma) value as 1.352 and 1.528.

CONCLUSION

Genetic and environmental hazard factors had a co-effect on the development of breast cancer while genetic polymorphisms of GSTT1 and DDT/HCH expressed an interaction to breast cancer.

Maternal pregnancy serum level of heptachlor epoxide, hexachlorobenzene, and beta-hexachlorocyclohexane and risk of cryptorchidism in offspring

Prenatal exposure to environmental endocrine disrupters has been postulated to cause adverse effects on male reproductive health. Exposure to organochlorine pesticides with anti-androgenic and estrogenic potency has been shown to interfere with the sex-hormone-dependent process of testicular descent in animal models. We examined the relation between serum levels of the pesticides heptachlor epoxide (HCE), hexachlorobenzene (HCB), and beta-hexachlorocyclohexane (beta-HCCH) in pregnant women, and the occurrence of cryptorchidism in their sons. These three pesticides were previously suggested as risk factors for cryptorchidism. In a nested case-control design, we compared serum levels between mothers of cases (n = 219) and controls (n = 564), selected from the Collaborative Perinatal Project, a US birth cohort study of pregnancies in 1959-1966. The offspring of mothers with HCE levels above the 90th percentile compared to those below the 10th percentile had an adjusted odds ratio of cryptorchidism of 1.2 (95% confidence interval 0.6-2.6); for beta-HCCH the odds ratio was 1.6 (0.7-3.6). For HCB the adjusted odds ratio was near one. These results provide little support for an association of cryptorchidism with exposure to low levels of HCE or HCB. For beta-HCCH the findings were somewhat suggestive of an association but were inconclusive.

Quantification of low levels of organochlorine pesticides using small volumes (<or=100 microl) of plasma of wild birds through gas chromatography negative chemical ionization mass spectrometry

A solid phase extraction and gas chromatography with negative chemical ionization mass spectrometry in scan mode (GC-NCI-MS) method was developed to identify and quantify for the first time low levels of organochlorine pesticides (OCs) in plasma samples of less than 100 microl from wild birds. The method detection limits ranged from 0.012 to 0.102 pg/microl and the method reporting limit from 0.036 to 0.307 pg/microl for alpha, gamma, beta and delta-hexachlorocyclohexane (HCH), heptachlor, aldrin, heptachlor epoxide, endosulfan I, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), dieldrin, endrin, endosulfan-II, endrin-aldehyde and endosulfan-sulfate. Pesticide levels in small serum samples from individual Falco sparverius, Sturnella neglecta, Mimus polyglottos and Columbina passerina were quantified. Concentrations ranged from not detected (n/d) to 204.9 pg/microl for some OC pesticides. All levels in the food web in and around cultivated areas showed the presence of pesticides notwithstanding the small areas for agriculture existing in the desert of Baja California peninsula.

Factors predicting organochlorine pesticide levels in pregnant Latina women living in a United States agricultural area

Organochlorine (OC) pesticide use was restricted starting in the 1970s in developed countries and the 1980s and 1990s in developing countries. Current exposure to OC pesticides - dichlorodiphenyltrichloroethane (DDT), lindane (99% pure gamma-hexachlorocyclohexane (gamma-HCH)), hexachlorobenzene (HCB) - occurs on a limited basis. We measured para, para' (p,p')-DDE, p,p'-DDT, ortho, para' (o,p')-DDT, HCB, beta (beta)-HCH (the most persistent isomer of technical-grade HCH) and gamma-HCH in serum from 426 low-income pregnant Latina women living in an agricultural community in California. Detection frequencies were 94% to 100%. Median levels (ng/g lipid) of p,p'-DDE (1,052), p,p'-DDT (13), beta-HCH (37) and HCB (65) were significantly higher than United States population levels. Multivariate analyses of p,p'-DDE, p,p'-DDT, o,p'-DDT, beta-HCH and HCB indicate that time spent living outside the United States and birthplace in an area of Mexico with recent use of OC pesticides were significant predictors of exposure. Time spent living in the United States was associated with increased serum levels of p,p'-DDE and beta-HCH, but the increase for each year lived in the United States was lower than for each year lived outside the United States. There was no difference between the increase of HCB levels over time spent in or outside the United States, suggesting current and thus preventable exposure routes. However, we observed no associations between serum levels of any OC compound and current intake of saturated fat or agricultural take-home exposure risk factors. Lactation history and recent weight gain were negatively associated with serum levels of some, but not all OC compounds studied. Smoking history was borderline associated with elevated HCB levels. We observed no significant associations with body mass index. Although the weight of evidence from this study indicates that most exposure occurred before moving to the United States, the results for HCB indicate the possibility of ongoing exposure in this country.

Factors predicting organochlorine pesticide levels in pregnant Latina women living in a United States agricultural area

Organochlorine (OC) pesticide use was restricted starting in the 1970s in developed countries and the 1980s and 1990s in developing countries. Current exposure to OC pesticides - dichlorodiphenyltrichloroethane (DDT), lindane (99% pure gamma-hexachlorocyclohexane (gamma-HCH)), hexachlorobenzene (HCB) - occurs on a limited basis. We measured para, para' (p,p')-DDE, p,p'-DDT, ortho, para' (o,p')-DDT, HCB, beta (beta)-HCH (the most persistent isomer of technical-grade HCH) and gamma-HCH in serum from 426 low-income pregnant Latina women living in an agricultural community in California. Detection frequencies were 94% to 100%. Median levels (ng/g lipid) of p,p'-DDE (1,052), p,p'-DDT (13), beta-HCH (37) and HCB (65) were significantly higher than United States population levels. Multivariate analyses of p,p'-DDE, p,p'-DDT, o,p'-DDT, beta-HCH and HCB indicate that time spent living outside the United States and birthplace in an area of Mexico with recent use of OC pesticides were significant predictors of exposure. Time spent living in the United States was associated with increased serum levels of p,p'-DDE and beta-HCH, but the increase for each year lived in the United States was lower than for each year lived outside the United States. There was no difference between the increase of HCB levels over time spent in or outside the United States, suggesting current and thus preventable exposure routes. However, we observed no associations between serum levels of any OC compound and current intake of saturated fat or agricultural take-home exposure risk factors. Lactation history and recent weight gain were negatively associated with serum levels of some, but not all OC compounds studied. Smoking history was borderline associated with elevated HCB levels. We observed no significant associations with body mass index. Although the weight of evidence from this study indicates that most exposure occurred before moving to the United States, the results for HCB indicate the possibility of ongoing exposure in this country.

Maternal hair--an appropriate matrix for detecting maternal exposure to pesticides during pregnancy

The detection of exposure of pregnant women to toxicants in the environment is important because these compounds can be harmful to the health of the woman and her fetus. The aim of this study was to analyze for pesticides/herbicides in paired maternal hair and blood samples to determine the most appropriate matrix for detecting maternal exposure to these compounds. A total of 449 pregnant women were prospectively recruited at midgestation from an agricultural site in the Philippines where a preliminary survey indicated significant use at home and on the farm of the following compounds: propoxur, cyfluthrin, chlorpyrifos, cypermethrin, pretilachlor, bioallethrin, malathion, diazinon, and transfluthrin. Paired maternal hair and blood samples were obtained from each subject upon recruitment into the study (midgestation) and at birth and were analyzed for the above compounds, as well as lindane and DDT [1,1,1-trichloro-2-2-bis(p-chlorophenyl) ethane], and some of their known metabolites by gas chromatography/mass spectrometry. The highest exposure rate was seen for propoxur and bioallethrin and maternal hair analysis provided the highest detection rate for these two compounds, compared to blood, at both time periods: (1) At midgestation, 10.5% positive for propoxur in hair compared to 0.7% in blood (P<0.001) and for bioallethrin, 11.9% positive in hair compared to 0% in blood (P < or = 0.001), and (2) at birth, 11.8% positive for propoxur in hair compared to 4% in blood (P < or = 0.001) and for bioallethrin, 7.8% in hair compared to 0% in blood (P < or = 0.001). A small number of maternal hair samples were also positive for malathion, chlorpyrifos, pretilachlor, and DDT. Only a few of the pesticide metabolites were detected, principally 3-phenoxybenzoic acid, malathion monocarboxylic acid, and DDE [1,1,dichloro-2-2-bis(p-chlorophenyl)ethylene], and they were mostly found in maternal blood. There was a significant association between the use of the home spray pesticide, Baygon, and propoxur in maternal hair at birth (P=0.001) and between the use of a slow-burning mosquito coil and the presence of bioallethrin in maternal hair at midgestation and at birth (P=0.001, P < or = 0.041, respectively). There is significant exposure of the pregnant woman to pesticides, particularly to pesticides that are used at home. Our study demonstrates the advantages of analyzing maternal hair as a readily available biologic matrix for studying maternal exposure to toxicants in the environment, compared to blood. For propoxur, there was a 3- to 15-fold higher detection rate of the pesticide in maternal hair as compared to blood. As for the other pesticides, bioallethrin, malathion, chlorpyrifos, and DDT were exclusively found in maternal hair compared to blood. On the other hand, pesticide metabolites were infrequently found in maternal hair or maternal blood. Pesticides in blood most likely represent acute exposure, whereas pesticides in hair represent past and/or concurrent exposure. The high sensitivity, wide window of exposure, availability, and ease of hair collection are distinct advantages in using hair to detect exposure to pesticides among pregnant women. However, pesticides in maternal hair may also be secondary to passive exposure and therefore not truly representative of the internal pesticide dose. Finally, the analysis of maternal hair for pesticides as an index of maternal exposure to pesticides in the environment allows the institution of measures to prevent further exposure during pregnancy.

Childhood aplastic anaemia in Lucknow, India: Incidence, organochlorines in the blood and review of case reports following exposure to pesticides

OBJECTIVES

A hospital-based case-control study, the first in India, was conducted to determine the incidence of childhood aplastic anaemia in and around Lucknow in the backdrop of organochlorine levels in the blood and review the database for any association between the disease and exposure to pesticides.

DESIGN AND METHODS

A total of 25 cases of childhood aplastic anaemia were identified as per established criteria and enrolled over the study period of 1 year. Their blood organochlorine levels were determined using a gas-liquid chromatograph equipped with an electron capture detector.

RESULTS

The annual incidence of childhood aplastic anaemia in and around Lucknow was found to be 6.8 cases per million which is higher than many countries (e.g., France, Brazil, UK, and United States) but lower than those reported in Sweden, China and an European-Israeli collaborative study. Blood levels of alpha-HCH, gamma-HCH, delta-HCH, total-HCH, and p, p'-DDE were higher in children with aplastic anaemia than in those of controls; only alpha-HCH differed significantly (P < 0.05).

CONCLUSIONS

Although this pilot study, with limited statistical power, did not support any association between exposure to organochlorines and risk of childhood aplastic anaemia, a possible association between the two could not be ruled out in view of several cases identified following exposure to pesticides.

A tumor in the medulla oblongata producing beta-HCG and AFP

A 23 year-old woman presented with dysarthria, hoarseness, dysphasia, ataxia and dyspnoea. MRI showed a mass of heterogeneous intensity at the dorsal medulla oblongata. Laboratory studies revealed high serum alpha-fetoprotein (AFP) and beta-subunit human chorionic gonadotropin (beta-HCG) levels. No other tumours were found on systemic investigation. An intracranial non-germinomatous germ cell tumour (NGGCT) was strongly suspected. The patient received combination chemotherapy using ifosfamide, cisplatin, and etoposide and local irradiation to a total of 52 Gy. Serum AFP and beta-HCG levels normalized after four cycles of chemotherapy and she became asymptomatic apart from mild postural hypotension. A follow-up MRI showed only a tiny residual lesion in the medulla oblongata, which has been stable for more than three years. Surgical resection should be carefully considered in patients with brainstem tumours with elevation of serum tumour markers as chemo- and radiotherapy may be effective for brainstem NGGCT.

Whole body action of xenoestrogens with different chemical structures in estrogen reporter male mice

The present work tested the estrogenic activity of three weak environmental estrogens p,p'DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane], p,p'DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] and betaBHC [beta-benzene-hexachloride] in the transgenic estrogen-reporter mouse model (ERE-tK-LUC). By a time dependent analysis of the transgenic reporter expression (luciferase), we showed that all these chemicals modulated the estrogen receptors (ERs) in the whole body, although with a different efficacy and depending upon the tissue analyzed. Peak activity was registered at 16 h of treatment with 5000 microg/kg of each compound. Organochlorines are lipophylic molecules that accumulate in fat. During weight loss they are mobilized and their concentration increases in blood. We tested whether after experimental accumulation in fat tissue, followed by a 48 h period of fasting, these compounds could be modulated to reach sufficient levels to activate the ERs in target tissues. This experimental setting produced results that were different from those obtained following acute treatments. In loaded mice, fasting induced betaBHC mobilization resulted in strong ER activation in the liver, lung, eye, cerebellum, hypothalamus and cortex. p,p'DDT mobilization had no effect in these tissues, but efficiently acted in the testis, where, on the contrary, betaBHC inhibited reporter expression. During fasting, betaBHC, p,p'DDT and the metabolite p,p'DDE increased in blood concentration, from 2.7 +/- 0.36, 0.65 +/- 0.01 and 0.48 +/- 0.06 microg/ml to 9.51 +/- 1.1, 4.98 +/- 0.77 and 6.0 +/- 0.71 microg/ml, respectively. We conclude that these organochlorines modulate differently the expression of estrogen regulated genes in a tissue- and compound-specific manner and that their action is dependent on the energy balance. Moreover, we show that this mouse model is suitable to detect the estrogenic activity of chemicals with variable structures such as alkyl phenols and polychlorobiphenyls.

Age at natural menopause and exposure to organochlorine pesticides in Hispanic women

A cross-sectional study was conducted to evaluate the relationship between exposure to selected organochlorine pesticides (OCP) (p,p'-DDT, p',p'-DDE, dieldrin, hexachlorobenzene, beta-hexachlorocyclohexane [beta-HCH], oxychlordane, trans' nonachlor) and age at natural menopause in a sample of 219 menopausal women participating in the Hispanic Health and Nutrition Examination Survey in 1982-1984. Information on age at menopause, reproductive history, demographic variables, and potential confounding variables was collected via interview. Analysis of variance was employed to compare adjusted mean age at natural menopause among women by category of serum OCP level. Serum levels of p,p'-DDT, p,p'-DDE, beta-HCH, and trans-nonachlor were associated with a younger age at menopause. In particular, women with exposure levels in the highest exposure categories (serum p,p'-DDT > or = 6ppb, beta-HCH > or = 4ppb, or trans-nonachlor > or = 2ppb) had an adjusted mean age at menopause on average 5.7, 3.4, and 5.2 yr earlier, respectively, than women with serum levels of these pesticides below the detection limit. Women with serum p,p'-DDE levels greater than 23.6 ppb (highest quintile) had an adjusted mean age at menopause 1.7 yr earlier than women with serump,p'-DDE levels less than 5.5 ppb (lowest quintile). However, no consistent dose-response effect was apparent across low, medium, and high exposure categories. Interactions were detected for p,p'-DDT in combination with beta-HCH, trans-nonachlor, or oxychlordane, as well as beta-HCH in combination with oxychlordane.

Placental site trophoblastic tumor in a late recurrence of a nonseminomatous germ cell tumor of the testis

Placental site trophoblastic tumor (PSTT) is a well-defined entity in the female genital tract. In the male genital tract, a single case of PSTT in the testis of a young boy has been reported. Despite its very rare occurrence, PSTT of the testis has been incorporated in the latest WHO classification of tumors of the male genital tract. In this article, a case of a PSTT in a late retroperitoneal recurrence of a testicular nonseminomatous germ cell tumor in an adult male patient is presented. The tumor was discovered due to an elevated serum level of beta-human chorionic gonadotropin 4 years after chemotherapy. Upon review of the primary testicular tumor, small foci of intermediate trophoblastic tumor cells were discerned. This case illustrates that tumor cells resembling intermediate trophoblastic cells may metastasize to regional retroperitoneal lymph nodes. Because of their resistance to chemotherapy, these cells may invade surrounding tissue in due time, acquiring the typical morphology of PSTT.

Ectopic pregnancy diagnosis and the pseudo-sac

OBJECTIVE

To evaluate the impact of an ultrasound finding of a pseudo-sac (PS), a uterine sac without a double decidual ring or a yolk sac, on the management of cases with possible ectopic pregnancy.

DESIGN

A retrospective review of a series of cases.

SETTING

A general hospital.

PATIENT(S)

Seventy-seven patients who had a diagnostic laparoscopy over a period of 3 years for suspected ectopic pregnancy.

MAIN OUTCOME MEASURE(S)

A logistic regression analysis was conducted to evaluate the effect of the ultrasound finding of a PS on predicting a negative finding at laparoscopy.

RESULT(S)

The report of a PS is significantly associated with a false-positive diagnosis of ectopic pregnancy.

CONCLUSION(S)

A diagnosis of PS should not be interpreted as indicative of an ectopic pregnancy because radiological differentiation between an early intrauterine pregnancy failure and an ectopic pregnancy is not possible.

Current internal exposure to pesticides in children and adolescents in Germany: blood plasma levels of pentachlorophenol (PCP), lindane (gamma-HCH), and dichloro(diphenyl)ethylene (DDE), a biostable metabolite of dichloro(diphenyl)trichloroethane (DDT)

Pesticides are widely used throughout the world in agriculture to protect crops, and in public health to control diseases transmitted by animal vectors or intermediate hosts. After the prohibition of organochlorines such as DDT internal exposure of the general population to the organochlorines has been reduced markedly. Herein, current internal exposure of children and adolescents in an urban area in Germany to PCP, lindane, and DDT/E is reported. One hundred and thirty children and adolescents took part in this voluntary investigation. All of them stated they had never used pesticides in their homes or for medical reasons. Blood plasma was analysed for pentachlorophenol (PCP), lindane (gamma-HCH), and dichloro(diphenyl)ethylene (DDE), a biostable metabolite of dichloro(diphenyl)trichloroethane (DDT), using gas chromatography/electron capture detection according to well established methods approved by the Deutsche Forschungsgemeinschaft. Median (and 95th percentiles) in the age groups < 6, 6- < 12, and 12- < 18 years of age were (microgram/l): DDE: 0.75 (4.45), 0.95 (5.04), 0.89 (8.77); DDT: < 0.1 (0.22), < 0.1 (0.25), < 0.1 (0.30); PCP: 2.48 (17.32), 2.69 (5.85), 2.08 (8.04); lindane: < 0.1 (0.12, < 0.1 (0.08), < 0.1 (0.09). High levels of internal exposure to DDT in two girls were probably obtained during a holiday stay in India; high PCP-levels in two other girls were caused by a leather jacket impregnated with PCP, and a holiday abroad, respectively. Current background levels of internal exposure to organochlorine insecticides in children and adolescents in Germany are quantified. Exposure to these substances in the general population is thought to occur mainly via residues in food, which are low in general, today. In special cases, however, individual exposures may be dominated by other sources, i.e. impregnated leather clothes.

[Changes in concentrations of organochloride compounds in women from Flix, Tarragona [Spain]]

The population of Flix (region of Ribera del Ebro, Tarragona) is highly exposed to hexachlorobenzene (HCB) due to the closeness of an electrochemical factory. Although the degree of HCB contamination in this population is still high, concentrations of HCB in the sera of women aged 18-40 years from 1997 to 1999 were 61% lower than those observed in 1994 (4.1 ng/ml vs. 10.6 ng/ml). Concentrations of dichlorodiphenyl dichloroethane (p,p'-DDE) and beta-hexachlorocyclohexane (beta-HCH) also decreased, although the difference was not statistically significant. In contrast, concentrations of polychlorinated biphenyls (PCB) in the period 1997-1999 showed a nonsignificant increase compared with those in 1994.

Predictive value of human biomonitoring in environmental medicine: experiences at the outpatient unit of environmental medicine (UEM) of the University Hospital Aachen, Germany

There is little data on the distribution of biomonitoring parameters in patients at outpatient Units of Environmental Medicine (UEM). We evaluated the biomonitoring parameters of 646 UEM outpatients from our University Hospital 1988-1998. Few patients were exposed to specific substances. Data of patients who were not obviously exposed was analysed statistically (geometric mean, standard deviation, median, 95th percentile). Results were compared with reference values in literature. Normal distribution of biomonitoring parameters was rare. 95th percentiles for arsenic, chromium, selenium, zinc, phenol and toluene were below standard, 95th percentiles for copper and mercury above, and 95th percentiles for lead, cadmium, pentachlorophenol, lindane, and beta-hexachlorocyclohexane were within the published range of reference values. Thallium as well as most volatile organic compounds analyzed were below detection levels. Aluminum and fluorine exposure was rarely analysed. In view of these results, it is concluded that the indication for biomonitoring needs to be stringent as levels of biomonitoring parameters are generally not risen in patients of the UEM.

Serum levels of beta-hexachlorocyclohexane, hexachlorobenzene and polychlorinated biphenyls and breast cancer in Mexican women

Information on the association between exposure to beta-hexachlorocyclohexane (beta-HCH), hexachlorobenzene (HCB) or polychlorinated biphenyls (PCBs) and the incidence of breast cancer is inconclusive. However, exposure to such compounds is a public health concern in Mexico and is subject to recent regulation. Serum levels of beta-HCH, HCB and PCBs were analysed in 95 histologically confirmed breast cancer cases and 95 hospital controls, 20-79 years of age, from Mexico City, enrolled between March 1994 and April 1996. After adjusting for established risk factors, there was no evidence of a relationship between beta-HCH, HCB and PCBs and breast cancer risk (OR for beta-HCH tertile 3 versus tertile 1: 1.05 95% CI 0.46-2.40; OR for HCB tertile 3 versus tertile 1: 0.46 95% CI 0.20-1.07; OR for PCBs 1.31 95% CI 0.33-5.21 for the high category of exposure). This study lends no support to the case for a role for beta-HCH, HCB or PCBs in breast cancer aetiology.

Residuals of beta-hexachlorocyclohexane, dichlorodiphenyltrichloroethane, and hexachlorobenzene in serum, and relations with consumption of dietary components in rural residents in Japan

To estimate levels of organochlorine residuals in the Japanese population and the contribution of dietary factors to these levels, we determined serum levels of beta-hexachlorocyclohexane (beta-HCH), hexachlorobenzene (HCB), p,p'-dichlorodiphenyldichloroethane (p,p'-DDD), 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (p,p'-DDE) and p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) in 41 volunteers (14 men and 27 women) in a rural area of Northern Japan. These organochlorine levels were measured using gas-chromatography mass-spectrometry. By a self-administered dietary history questionnaire, the usual dietary intake was estimated. Their median levels (range) were as follows: beta-HCH, 0.50 (0.05-1.50); HCB, 0.20 (0.02-0.70); and total DDT (p,p'-DDE + p,p'-DDT), 5.0 (0.9-31.0) ng/ml serum. Levels of p,p'-DDD were detected in only seven subjects (0.05-0.6 ng/ml serum). The beta-HCH levels were increased with rice and milk intakes, but the least squares means were not simply increased according to the quartile of the intakes. Concerning HCB, fish intake showed a borderline significant correlation (0.20, P = 0.052). In terms of total DDT, intakes of meat, fish, vegetable and milk showed a positive relationship, although none of them provided statistically significant results. No other statistically significant relation between any organochlorines and any food intakes examined was observed in this study. The present study suggests that organochlorine compounds are transported into the human body via foods in the Japanese population. Their effects on health should thus be investigated and monitored.

Early childhood determinants of organochlorine concentrations in school-aged children

We investigated whether early childhood factors such as breast-feeding, parity, and smoking contribute to the variation of organochlorine compounds (OC: dichlorodiphenyldichloroethene, hexachlorobenzene, beta-hexachlorocyclohexane, and the sum of polychlorinated biphenyls including the congeners 101, 118, 138, 153, 170, 180, 183, and 187) at approximately 7 y of age. OC were measured in whole blood of 350 children. Pregnancy characteristics and the child's living conditions were gathered by questionnaires administered to the parents and interviews with the mother. Height and weight were determined during the medical examination. Exclusion of incomplete data and nonbiologic children of the mothers yielded a sample of 337 children. We applied regression analysis with indicator variables, controlling for confounders. No systematic association was detected for birth order or maternal smoking during pregnancy. The OC concentrations are diluted in children with a higher body mass index (>18 kg/m(2)). We found a strong, dose-dependent relationship between the duration of breast-feeding (none, 1-4 wk, 5-8 wk, 9-12 wk, >12 wk) and the concentration of all five OCs. Of the potential determinants analyzed, more of the variance of the OC concentration is accounted for by breast-feeding than by any other variable. Exclusive breast-feeding beyond 12 wk was associated with a doubling of OC whole blood concentration compared with bottle-fed children (dichlorodiphenyldichloroethene, 0.28 microg/L versus 0.55 microg/L; beta-hexachlorocyclohexane, 0.05 microg/L versus 0.14 microg/L; hexachlorobenzene, 0.14 microg/L versus 0.25 microg/L; sum of polychlorinated biphenyls, 0.25 microg/L versus 0.55 microg/L). These findings indicate that breast-feeding can lead to an extended duration of increased OC exposure in childhood.

Associations of blood levels of PCB, HCHS, and HCB with numbers of lymphocyte subpopulations, in vitro lymphocyte response, plasma cytokine levels, and immunoglobulin autoantibodies

Pentachlorophenol (PCP), hexachlorocyclohexane-[alpha], -beta, and -[gamma] (HCH-[alpha], -beta, and -[gamma]), polychlorinated biphenyls (PCBs), and hexachlorobenzene (HCB) are widely distributed industrial chemicals. They are suspected to induce immunologic impairments in exposed individuals. We examined dose-response relationships of blood levels of these chemicals with cellular (numbers of lymphocyte subpopulations, in vitro lymphocyte response) or humoral (plasma cytokine levels, immunoglobulin autoantibodies) immunologic dysfunctions. We studied 146 patients who had been occupationally exposed primarily to PCBs for more than 6 months. Lymphocyte subpopulations, in vitro responses to mitogens and allogeneic stimulator cells, plasma neopterin, cytokines, soluble cytokine receptors, soluble adhesion molecules, anti-Ig autoantibodies, and liver transaminases were determined. Blood levels of the different compounds were strongly correlated with one another. There were only weak dose-response relationships between blood levels of PCBs with cellular immune parameters, and of HCHs and HCB with humoral immune parameters. An exception was the statistically significant negative association of HCB with interferon-[gamma] (IFN-[gamma]), indicating that HCB has a significant impact on Th1 lymphocytes. Patients with HCB blood levels above the mean of 1,109 ng/L more often had undetectable IFN-[gamma] blood levels than patients below the mean. Patients with increased PCB 138 (> 710 ng/L) had more frequently undetectable interleukin-4 blood levels than patients with PCB 138 below the mean, and patients with increased PCB 101 (> 31 ng/L) more often had low DR+ cell counts in the blood (< 190/microL) than patients with PCB 101 below the mean. To assess possible cumulative effects, we compared patients who had blood levels of all compounds below background with patients who had blood levels of all compounds above background. Patients with low or absent blood levels of the compounds studied had higher IFN-[gamma] plasma levels, providing some evidence for a cumulative effect of several weakly active compounds. In conclusion, exposure to PCBs, HCB, or HCHs is associated with weak immunologic abnormalities. These results contrast with those obtained in earlier studies of blood levels of PCP, which showed a strong dose-dependent relationship with immunologic impairments. Our data suggest that long-term exposure of patients to HCB suppresses IFN-[gamma] production.

Potential pathways and exposure to explain the human body burden of organochlorine compounds: a multivariate statistical analysis of human monitoring in Würzburg, Germany

By means of multivariate statistical analysis of human monitoring in the vicinity of Würzburg it is examined whether the organochlorine levels in blood data of 309 persons can in part be explained by pollution from outdoor and/or indoor air. Although diet is the main source for intake this study concentrated on the remaining sources. Using 12 personal and geographical variables, which describe some aspects or components of indoor or outdoor exposure, the quantities of the different pathways for the intake are calculated and shown. Besides the impact of the indoor air, which can be pointed out for intake at the workplace for some PCB-congeners, also the hypothesis of the existence of an intake from outdoor air for some organochlorine compounds cannot be rejected. Here, the origin is the spatial variation of the pollution, which can be directly traced back to micro-climatic processes, local relief conditions, and the functional set-up of the town.

Prolonged phenobarbital pretreatment abolishes the early oxidative stress component induced in the liver by acute lindane intoxication

Lindane administration to rats (60 mg/kg b.w.) led to an enhancement in the oxidative stress status of the liver at 4 h after treatment, characterized by increases in hepatic thiobarbituric acid reactants (TBARS) formation and chemiluminescence, reduced glutathione (GSH) depletion, and diminution in the biliary content and release of GSH. These changes were observed in the absence of changes in either microsomal functions (cytochrome P450 content, NADPH-dependent superoxide radical production, and NADPH-cytochrome P450 reductase or NADPH oxidase activities) or in oxidative stress-related enzymatic activities (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and glutathione-S-transferases), over control values. Phenobarbital (PB) administration (0.1% in drinking water; 15 days) elicited an enhancement in liver microsomal functions, lipid peroxidation, and GSH content, without changes in oxidative stress-related enzymatic activities, except for the elevation in those of glutathione reductase and glutathione-S-transferase, compared to control rats. Lindane given to PB-pretreated rats did not alter liver microsomal functions, lipid peroxidation, glutathione status, or oxidative stress-related enzymatic activities, as compared to PB-pretreated animals. In addition, lindane induced periportal necrosis with hemorrhagic foci in untreated rats, but not in PB-pretreated animals. It is concluded that the early oxidative stress response of the liver to lindane and hepatic injury are suppressed by PB pretreatment via induction of microsomal enzymes in all zones of the hepatic acinus. reserved.

Long-term exposure to wood-preserving chemicals containing pentachlorophenol and lindane is related to neurobehavioral performance in women

BACKGROUND

The adverse neurobehavioral effects of long-term low exposure to wood-preserving chemicals (WPC) containing solvents, pentachlorophenol (PCP) and gamma-hexachlorocyclohexane (gamma-HCH; lindane), and other neurotoxicants were investigated in a neuropsychological group study.

METHODS

Out of a population of 2,000 women visiting the outpatient practice of a gynecological department, a sample of 15 women aged 31-56 (mean 43) with long-term exposure to WPC verified by self-report, biological monitoring, and environmental samples was investigated. Fifteen controls aged 42 (31-56) years were drawn from the same population and pair-wise matched with respect to sex, age, education, and estimated intelligence.

RESULTS

For the exposed group, mean PCP serum level was 43.6 micrograms/l and mean gamma-HCH blood level was 0.085 microgram/l. Mean duration of exposure was 10 (5-17) years. Intellectual functioning, attention, memory, and visuo-motor performance were examined, suggesting significant group differences in visual short-term memory (Benton Test; d = 1.5, P = .005), verbal memory (paired associate learning and Peterson paradigm; d = 4.3 and 1.6, P < .001), and an incidental learning task (d = 2.3; P = .001). Frequent subjective complaints as assessed by questionnaire were attenuated motivation (d = 1.7; P = .001), increased fatigue (d = 1.6; P = .001), distractibility (d = 1.0; P = .003), and depressed mood (d = 1.9; P = .004). PCP blood level was significantly associated with paired-associate learning, Benton Test, and reading/naming speed.

CONCLUSIONS

Long-term low-dose exposure to WPC in the domestic environment could be related to subjective complaints (attention, mood, and motivation) and to subtle alterations of neurobehavioral performance (e.g., working memory) in women.

Endocrine and reproductive function in ewes exposed to the organochlorine pesticides lindane or pentachlorophenol

The effects of lindane (LIN, gamma-hexachlorocyclohexane) and pentachlorophenol (PCP) on reproduction and general endocrine function were examined in breeding ewes as a model for wild and domestic ungulates, which may be exposed to low levels of pesticides that are potential endocrine-disrupting chemicals. Ewes (n = 13/group) were fed either a control untreated diet (CON), or a diet treated with LIN (1 mg/kg/d) or PCP (1 mg/kg/d) during the 5 wk prior to mating and throughout pregnancy and lactation. Mating response, ovulation rate, follicle and corpus luteum size, gestation length, pregnancy rate, lambing rate, and lamb birth weight were recorded. After weaning, 6 ewes from each group were bled at 15-min intervals for 8 h during the day and night and for 1 h before and 5 h after i.v. administration of gonadotropin-releasing hormone, thyroid-stimulating hormone (TSH), and adrenocorticotropin, to measure serum concentrations of luteinizing hormone, follicle-stimulating hormone, thyroxine (T4), and cortisol. Ewes were then killed and endocrine tissues examined histologically. Pregnancy rate as a result of matings taking place at the synchronized estrus was significantly decreased by the lindane treatment However, PCP and lindane did not markedly affect any other aspect of reproductive function studied. In PCP-treated ewes, serum concentrations of T4 were significantly reduced compared to control ewes during the day and night; however, the T4 response to TSH was not altered by PCP treatment. No other measured endocrine parameters were consistently affected by lindane or PCP. Thyroid follicle size was significantly increased in the LIN and PCP ewes compared to the control ewes. Low serum concentrations of T4 in the PCP ewes may have resulted in increased TSH secretion and increased thyroid follicle size. In conclusion, although pesticide treatments had no serious adverse effects on reproductive function in breeding ewes, PCP reduced T4 concentration, which in the long term could influence reproductive and general performance.

Chlorinated hydrocarbons in women with repeated miscarriages

This study was conducted to investigate a possible etiological role of chlorinated hydrocarbons in the pathogenesis of repeated miscarriages. The blood levels of chlorinated hydrocarbons [CHCs: pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, the dichlorodiphenyltrichloroethane (DDT) group, polychlorinated biphenyls] were determined in 89 women with repeated miscarriages, who were referred to the University Hospital of Obstetrics and Gynecology of Heidelberg for investigations between 1989 and 1993, and compared to a previously investigated reference population. In more than 20% of the women, at least one of the CHC levels exceeded the reference range. CHC levels did not differ significantly between women with primary or secondary and early or late miscarriages; neither did they differ between women with hormonal or immunological disorders as causes of repeated miscarriages or women with idiopathic repeated miscarriages. No significant associations were detected between CHC levels and further conceptions or the outcome of further pregnancies. As significant associations were found between increasing CHC blood concentrations and immunological and hormonal changes, CHCs may have an impact on the pregnancy course in certain cases.

Excitatory amino acid antagonists alleviate convulsive and toxic properties of lindane in mice

Pesticides acting at GABAA receptors may induce convulsions in man and animals, but the mechanisms responsible for their convulsant activity are not fully explained. The following excitatory amino acid antagonists were studied for their protective action in mice intoxicated with chlorinated hydrocarbon insecticide lindane (gamma-hexachlorocyclohexane): the competitive NMDA antagonist: 3-(2-carboxypiperazine-4-yl)propenyl-1- phosphonic acid (D-CPPene, 20 mg/kg), the non-competitive NMDA antagonist: dizocilpine (MK-801, 0.4 mg/kg), the glycine site antagonist of NMDA receptor: 2-phenyl-1,3-propane-diol dicarbamate (felbamate, 400 mg/kg) and the competitive AMPA antagonist: 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline (NBQX, 100 mg/kg). Systemic administration of an antagonist prior to lindane resulted in a strong anticonvulsant effect. D-CPPene, MK-801 and NBQX produced a marked increase of CD50 values of lindane for clonic convulsions. All the antagonists protected animals against tonic convulsions. Toxicity of lindane was potently reduced, as assessed 2, 24 and 120 hr after administration of the pesticide. Our results demonstrate that excitatory amino acid antagonists reduce convulsant properties and toxicity of lindane, suggesting that excitatory amino acid neurotransmission may be involved in its central action.

Some dietary predictors of plasma organochlorine concentrations in an elderly German population

Associations between reported consumption of animal products and chlorinated hydrocarbon concentrations were examined in 297 elderly people who lived in Germany. Consumption of beef and lamb was correlated positively with hexachlorobenzene (HCB), beta-hexachlorocyclohexane (beta-HCH), total polychlorinated biphenyls (PCBs), and total dichloro-diphenyl-trichloroethane (DDT) (r = .13-.19, p < .05). Consumption of saltwater fish was correlated positively with alpha-HCH, dieldrin, and PCBs (r = .12-.26, p < .05). Other univariate predictors were body mass index, plasma cholesterol, pork consumption, poultry consumption, and age. Multivariate linear models of predictors of each chlorinated species were constructed, and some form of meat was used as the main predictor; the sum of all meats (exclusive of fish) was the best predictor of dieldrin and In(alpha-HCH) concentrations. Beef and lamb consumption was a positive predictor of HCB, heptachlor epoxide, total DDT, and beta-HCH. Saltwater fish was the major dietary predictor of PCBs.

The percutaneous absorption and skin distribution of lindane in man. I. In vivo studies

1. The absorption and distribution of lindane through skin was examined using human volunteers. Two different preparations were employed, one with acetone as the vehicle and the other, a commercial product, consisting primarily of white spirit as the solvent base. 2. The mean peak plasma concentrations of lindane following exposure to the acetone and white-spirit based applications were 0.91 and 0.47 ng/ml, respectively. The similarity between these levels did not reflect the 40-fold higher dose of lindane in the acetone vehicle. White spirit enhanced the penetration of lindane with respect to the acetone vehicle, highlighting the influence of vehicle upon percutaneous absorption. Low levels of trichlorophenol glucuronide metabolites, but no lindane, were detected in the urine. 3. The exposure site was washed at 6 h to mimic a decontamination procedure at the end of a working day. The proportion of the applied dose unabsorbed by 6 h was 80% and 10% for the acetone and the white spirit-based formulation, respectively. Small areas of the exposed site were tape stripped at 6 and 24 h to assess any lindane that may be associated with the stratum corneum. High levels were observed in the stratum corneum at 6 h exposure (up to 30% of the applied dose for the white spirit based formulation). However, this level had decreased by 24 h (by at least 90% of the amount found at 6 h). A gauze or gauze/shirt combination covering the application site between 6 and 24 h did account for some of this loss of lindane from the stratum corneum attributed to friction and removal of exfoliated cells. The unaccounted proportion was presumed to have been absorbed through the skin into the systemic circulation. This demonstrates the absorption of chemicals can occur from a depot in the stratum corneum even following a wash procedure.

Simulation of lindane kinetics in rats

The kinetics of lindane were modelled in the male rat with a physiologically-based pharmacokinetic (PB-PK) model. The model was parameterized by using reference physiological parameter values and partition coefficients that were reported earlier in the literature. First order biotransformation and gastro-intestinal absorption constants for lindane were obtained by visually fitting the model to literature data on lindane disposition in vivo after a single oral dose. The model was validated by simulating the disposition of lindane in vivo after single intraperitoneal and chronic oral dosage and comparing simulated with experimental results. It was concluded that the present model can adequately simulate most of the reported data on lindane kinetics.

Hexachlorocyclohexanes in human blood serum

A simplified method allowing the determination of trace concentrations (ng/ml) of hexachlorocyclohexanes in human sera suitable for the analysis of large numbers of samples has been developed. Comparison of acid (conc. H2SO4,) and basic (5 M KOH) digestion has shown that good recoveries are obtained with the former when an internal standard, 1,2,4,5-tetrabromobenzene (TBB), is used to correct for volatilization losses. Good separation between alpha-, beta- and gamma-HCH isomers, TBB, hexachlorobenzene and some interfering compounds is obtained with DB-5 columns. The use of electron-capture detection (ECD) or negative ion chemical ionization mass spectrometry (NICI-MS) in the selected ion monitoring mode (m/z 71) provides sufficient sensitivity for quantitative determination. ECD is the most sensitive method for beta-HCH and NICI-MS for the other isomers. GC-NICI-MS is needed for the unambiguous determination of delta-HCH due to the coelution with one interfering compound. The method has been successfully applied to the analysis of a series of 625 samples collected in a population situated near the effluents of an organochlorinated solvent factory. The results have shown that beta-HCH is selectively accumulated in human sera and prompt to the preferential investigation of the toxic effects of this isomer in humans and mammals.

Regression of morphological alterations and oxidative stress-related parameters after acute lindane-induced hepatotoxicity in rats

Changes in rat liver oxidative stress-related parameters, morphological alterations, as well as circulating and tissue levels of lindane were studied 1-7 days after the administration of a single dose of 60 mg of lindane/kg. One day after lindane treatment, a significant enhancement in the oxidative stress status of the liver was observed, characterized by an increase in thiobarbituric acid reactants production and in the microsomal generation of superoxide radical (O.-2) coupled to cytochrome P450 induction, and a decrement in the activity of superoxide dismutase (SOD) and catalase. Consequently, the O.-2 production/SOD activity ratio was enhanced two-fold. In this condition, light microscopy studies revealed the incidence of liver lesions in periportal areas, together with significant changes at the mitochondrial level observed by electron microscopy, which coincide with the maximal levels of lindane in the liver, adipose tissue, plasma and whole blood. Changes in oxidative stress-related parameters observed after 1 day of lindane treatment regressed to normal from the third day and thereafter, together with the decrement in circulating and tissue levels of the insecticide. It is concluded that morphological and oxidative stress-related changes induced in the liver by acute lindane intoxication are readily reversible, depend on the hepatic content of the insecticide, and seem to be conditioned by the changes in O.-2 generation.