Exposure to organochlorine pesticides as a predictor to breast cancer: A case-control study among Ethiopian women.

Breast cancer (BC) is becoming one of the most prevalent non-infectious disease in low and middle income countries. The steady rise of BC incidence may be related to the different risk factors. Among many, rampant presence of environmental pollutants might be one of the risk factors. Therefore, the aim of this study is to investigate exposure to organochlorine pesticides as a risk factor to breast cancer. A case-control study design was employed among breast cancer patients and non-breast cancer individuals (controls). Blood samples were collected from 100 study participants (50 cases and 50 controls) followed by serum separation, extraction and cleanup using standard analytical procdures. The findings revealed that ten organochlorine pesticides were detected in the serum of the study participants. From the detected organochlorine pesticides, heptachlor was observed at higher concentration for breast cancer patients (6.90±4.37 µg/L) and controls (9.15±3.84 µg/L). Mean serum level of p,p'-DDE, p,p'-DDT, heptachlor, gamma-chlordane, endosulfan, and dibutyl-chlorendate were significantly higher in the serum of breast cancer patients than the controls. From the studied pesticides, p,p'-DDT and gamma-chlordane are significant predictors for BC, while, others are equivocal. A unit increment of the concentration of p,p'-DDT (AOR; 2.03, 95% CI: 1.041-3.969) increased the odds of developing breast cancer by two, while for gamma-chlordane (AOR;3.12, 95% CI; 1.186-8.203) by three. Our study results suggesting that, organochlorines are a risk factors for breast cancer in Ethiopia. Decreasing exposure to such organochlorines might have a significant public health relevance in reducing non-communicable chronic illnesses. Besides, continues monitoring of persistent organic pollutants using body biomarkers is important for disease prevention and device mitigation measures.

Insecticide use and risk of non-Hodgkin lymphoma subtypes: A subset meta-analysis of the North American Pooled Project.

Insecticide use has been linked to increased risk of non-Hodgkin lymphoma (NHL), however, findings of epidemiologic studies have been inconsistent, particularly for NHL subtypes. We analyzed 1690 NHL cases and 5131 controls in the North American Pooled Project (NAPP) to investigate self-reported insecticide use and risk of NHL overall and by subtypes: follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL) and small lymphocytic lymphoma (SLL). Odds ratios (OR) and 95% confidence intervals for each insecticide were estimated using logistic regression. Subtype-specific associations were evaluated using ASSET (Association analysis for SubSETs). Increased risks of multiple NHL subtypes were observed for lindane (OR = 1.60, 1.20-2.10: FL, DLCBL, SLL), chlordane (OR = 1.59, 1.17-2.16: FL, SLL) and DDT (OR = 1.36, 1.06-1.73: DLBCL, SLL). Positive trends were observed, within the subsets with identified associations, for increasing categories of exposure duration for lindane (Ptrend = 1.7 × 10-4 ), chlordane (Ptrend = 1.0 × 10-3 ) and DDT (Ptrend = 4.2 × 10-3 ), however, the exposure-response relationship was nonlinear. Ever use of pyrethrum was associated with an increased risk of FL (OR = 3.65, 1.45-9.15), and the relationship with duration of use appeared monotonic (OR for >10 years: OR = 5.38, 1.75-16.53; Ptrend = 3.6 × 10-3 ). Our analysis identified several novel associations between insecticide use and specific NHL subtypes, suggesting possible etiologic heterogeneity in the context of pesticide exposure.

Development of Biomonitoring Equivalents for chlordane and toxaphene with application to the general Canadian population.

Biomonitoring Equivalents (BEs) were developed for chlordane and toxaphene using one-compartment pharmacokinetic models and compared with biomonitoring data from the Canadian Health Measures Survey, Cycle 1 (2007-2009). A secondary objective was to examine the toxicities of the components of technical chlordane in a HEPG2 cell culture experiment. Oral reference doses were identified from national and international regulatory agencies and sources. Pharmacokinetic parameters were obtained from experimental data in rodent models. A set of BEs have been derived for the main chlordane isomers, cis-chlordane, trans-chlordane, cis-nonachlor, and trans-nonachlor, and the chlordane metabolite, oxychlordane. BEs were also derived for the main toxaphene isomers found in biota, Parlar No. 26, 50 and 62. Among the general Canadian population, no exceedances of chlordane or toxaphene BEs were observed. Based on the LC50 from the in vitro study, trans-nonachlor was the most toxic, and the trans-isomers were more toxic than the cis-isomers. The derived BE values can be used as screening guidelines to assess the risk of biomonitoring data in human populations. The results of an in vitro experiment suggest that trans-nonachlor is more toxic than technical chlordane and, therefore, the BE for this compound may need to be further lowered.

Prediagnostic serum organochlorine insecticide concentrations and primary liver cancer: A case-control study nested within two prospective cohorts.

Although experimental evidence indicates that certain organochlorine insecticides are hepatocarcinogens, epidemiologic evidence for most of these chemicals is very limited. We estimated associations, using prospectively collected sera, between organochlorine insecticide concentrations and cancer registry-identified primary liver cancer in two cohorts, one from the United States and one from Norway. In nested case-control studies, we used sera collected in the 1960s-1980s from 136 cases and 408 matched controls from the Kaiser Permanente Northern California Multiphasic Health Checkup (MHC) cohort and 84 cases and 252 matched controls from the population-based Norwegian Janus cohort. We measured concentrations of nine organochlorine insecticides/metabolites and markers of hepatitis B and C in sera. Adjusted odds ratios (OR) and 95% confidence intervals (CI) for tertiles of lipid-corrected organochlorines were calculated for each cohort using conditional logistic regression. Among MHC participants with sera from the 1960s, there was a suggestive exposure-response trend for trans-nonachlor (second and third tertile of analyte ORs = 1.63 and 1.95, respectively; p-trend = 0.08) and a nonsignificantly elevated risk for the highest tertile of oxychlordane (OR = 1.87). Among Janus participants with sera from the 1970s, we observed an apparent trend for p,p'-DDT (second and third tertile ORs = 1.70 and 2.14, respectively; p-trend = 0.15). We observed little consistency in patterns of association between the cohorts. We found limited evidence that exposure to p,p'-DDT and chlordane-related oxychlordane and trans-nonachlor may be associated with increased risk of primary liver cancer. However, the modest strength of these associations and their lack of concordance between cohorts necessitate caution in their interpretation.

Organochlorine pesticides and prostate cancer, Is there an association? A meta-analysis of epidemiological evidence.

PURPOSE: The results of epidemiological studies about exposure to organochlorine pesticides (OCPs) and risk of prostate cancer (PC) are inconclusive. We conducted a meta-analysis to evaluate the association between exposure to specific OCPs and PC. METHODS: We searched PubMed, Scopus, and Web of science databases for case-control and cohort studies published till March 2015 that provided data about exposure to OCPs and PC. We also contacted authors and hand-searched references of the included articles. We calculated pooled estimates using random effects model and explored heterogeneity between studies. RESULTS: We systematically reviewed 15 articles and based our meta-analysis on 10 articles covering nine case-control studies and a large prospective cohort study. Pooled estimates of PC for highest versus lowest exposed category to p,p'-DDE was 1.02 (0.69-1.35), I (2) = 12.7 %, p = 0.333, trans-nonachlor, 0.88 (0.45-1.31), I (2) = 0.00 %, p = 0.892, oxychlordane, 0.91 (0.46-1.35), hexachlorobenzene, 0.88 (0.18-1.57), I (2) = 36.0 %, p = 0.210 from combining results of studies that applied serum OCPs measurements among the general population. For DDT, stratifying studies by exposed population revealed homogeneity, pooled estimate for serum level measurement for the highest exposed versus the lowest exposed of the general population was 0.81 (0.95-1.26), I (2) = 0.00 %, p = 0.400, and for occupational exposure 1.30 (0.94-1.67), I (2) = 13.4 %, p = 0.315. A positive but also insignificant association was obtained for pooling results for high exposure to lindane among farmers and pesticide applicators, 1.56 (0.82-2.29), I (2) = 41.7 %, p = 0.180. CONCLUSIONS: The existing epidemiological data do not support the hypothesis that exposure to specific OCPs is associated with an increased incidence of PC in the general population.

Fetal exposure to chlordane and permethrin mixtures in relation to inflammatory cytokines and birth outcomes.

We sought to characterize the relationships between cord serum concentrations of chlordane and permethrin pesticides, inflammatory cytokines, gestational age, and size at birth. Umbilical cord serum levels of trans-nonachlor, oxychlordane, cis- and trans-permethrin, piperonyl butoxide, and cytokines (TNF-α, IFN-γ, IL-1ß, IL-2, IL-6, IL-8, IL-10, IL-12p70, GMCSF) were quantified in 300 newborns at the Johns Hopkins Hospital in Baltimore, MD (2004-2005). Principal component analyses were used to quantitate chlordane and permethrin mixtures and to identify independent cytokine components. Five cytokine components described 87% of the variance in cord serum cytokine levels; these (and predominant loadings) were as follows: (1) all 9 cytokines; (2) acute phase (IL-1ß, IL-6); (3) anti-inflammatory (IL-10); (4) TNF-α; and (5) IL-1ß. Of these, the TNF-α component was significantly associated with a 2-day decrease in gestational age. Chlordane was associated with lower levels of the pro-inflammatory IL-1ß [ß: -0.11 (-0.20, -0.02)]. Permethrin was negatively associated with the anti-inflammatory cytokine IL-10 [ß: -0.14 (-0.22, -0.05)]. Neither pesticides nor cytokines were significantly associated with birthweight, length, or head circumference, and pesticides were not associated with gestational age. Our findings suggest that chlordane and permethrin concentrations in cord blood may be associated with levels of inflammatory cytokines in the fetus.

Low dose of some persistent organic pollutants predicts type 2 diabetes: a nested case-control study.

BACKGROUND: Low doses of some persistent organic pollutants (POPs) associate cross-sectionally with type 2 diabetes, whereas associations with high POP exposures are inconsistent. OBJECTIVES: We investigated whether several POPs prospectively predict type 2 diabetes within the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. METHODS: Participants in this nested case-control study were diabetes free in 1987-1988. By 2005-2006, the 90 controls remained free of diabetes, whereas the 90 cases developed diabetes. Using serum collected in 1987-1988, we measured 8 organochlorine pesticides, 22 polychlorinated biphenyl congeners (PCBs), and 1 polybrominated biphenyl (PBB). We compared POP concentrations from CARDIA and the National Health and Nutrition Examination Survey (NHANES) in 2003-2004. We computed odds ratios (ORs) for incident diabetes using logistic regression analysis. RESULTS: Chlorinated POPs in CARDIA in 1987-1988 were much higher than corresponding NHANES 2003-2004 concentrations. POPs showed nonlinear associations with diabetes risk. The highest risk was observed in the second quartiles of trans-nonachlor, oxychlordane, mirex, highly chlorinated PCBs, and PBB153-a finding that suggests low-dose effects. We concentrated risk by summing these POPs and isolated very low concentrations of multiple POPs in the lowest sextile of the sum. The adjusted OR in the second sextile vs. the lowest sextile was 5.3 overall and 20.1 for body mass index > or = 30 kg/m2. CONCLUSIONS: Several POPs at low doses similar to current exposure levels may increase diabetes risk, possibly through endocrine disruption. Certain POPs may a play a role in the current epidemic of diabetes, which has been attributed to obesity.

Human erythrocytes are affected by the organochloride insecticide chlordane.

Chlordane is a widely used organochlorine insecticide. In order to evaluate its perturbing effect upon the morphology of human erythrocytes it was caused to interact with human red cells and molecular models of cell membranes. These consisted in bilayers of dimyristoylphosphatidylethanolamine (DMPE) and of dimyristoylphosphatidylcholine (DMPC), representative of phospholipid classes located in the inner and outer monolayers of the erythrocyte membrane, respectively. Scanning electron microscopy (SEM) observations indicated that this pesticide induced a significant alteration in the shape of the erythrocytes as they changed their discoid shape to spherocytes. According to the bilayer couple hypothesis, the shape changes induced in erythrocytes by foreign molecules are due to differential expansion of their two monolayers. The fact that chlordane produced spherocytes would indicate that the pesticide was equally located in the outer and the inner moieties of the red cell membrane. This conclusion was supported by the results obtained from X-ray diffraction studies. These showed that the hydrophobic and polar head regions of DMPC bilayers were perturbed when the insecticide was in a 1:10 molar ratio with respect to the lipid. These results were confirmed by the fluorescence experiments performed in DMPC large unilamellar vesicles (LUV). Chlordane produced a sharp decrease in the anisotropy and general polarization parameters in the 0-0.1 mM range, implying an increase in the fluidity at the acyl chain and polar region of DMPC. On the other hand, the bilayer structure of DMPE was perturbed in a fashion similar to that observed by X-ray diffraction in DMPC, a fact that explains the morphological change induced by chlordane to the human erythrocytes.

Activation of human neutrophils by chlordane: induction of superoxide production and phagocytosis but not chemotaxis or apoptosis.

We have recently reported that human neutrophils are important targets of different xenobiotics, including chemicals of environmental concern. In the present study, we found that chlordane was not toxic for human neutrophils incubated for up to 24 h with concentrations ranging from 0.1 to 50 microg/ml. Chlordane was found to induce neutrophil superoxide production (O2-) in a concentration-dependent fashion and its potency to induce this response was found to be similar to phorbol 12-myristate 13-acetate (PMA), a classical neutrophil agonist. The use of different transduction signal inhibitors (genistein, pertussis toxin, staurosporine, and calphostin C) indicates that, as for PMA, chlordane induces O2- production via protein kinase C (PKC). In this respect, staurosporine and calphostin C were found to inhibit chlordane- and PMA-induced O2- production by 65% and 72%, and by 83% and 85%, respectively. Chlordane was also found to significantly enhance neutrophil phagocytosis of opsonized sheep red blood cells (SRBCs). Despite these effects, chlordane did not alter neutrophil apoptosis as assessed by cytology (Diff-Quick staining) and by flow cytometry (CD-16 expression). In addition, chlordane did not alter neutrophil chemotaxis (48-well Boyden chamber). Cells were, however, responsive as they were activated by the well-characterized interleukin (IL)-8 chemokine. We conclude that chlordane can activate O2- production by a PKC-dependent mechanism and induce phagocytosis without altering chemotaxis and apoptosis. Chlordane must be added to a growing list of environmental contaminants that share some pro-inflammatory properties.

Embryonic treatment with xenobiotics disrupts steroid hormone profiles in hatchling red-eared slider turtles (Trachemys scripta elegans).

Many compounds in the environment capable of acting as endocrine disruptors have been assayed for their developmental effects on morphogenesis; however, few studies have addressed how such xenobiotics affect physiology. In the current study we examine the effects of three endocrine-disrupting compounds, chlordane, trans-nonachlor, and the polychlorinated biphenyl (PCB) mixture Aroclor 1242, on the steroid hormone concentrations of red-eared slider turtle (Trachemys scripta elegans) hatchlings treated in ovo. Basal steroid concentrations and steroid concentrations in response to follicle-stimulating hormone were examined in both male and female turtles treated with each of the three compounds. Treated male turtles exposed to Aroclor 1242 or chlordane exhibited significantly lower testosterone concentrations than controls, whereas chlordane-treated females had significantly lower progesterone, testosterone, and 5[alpha]-dihydrotestosterone concentrations relative to controls. The effects of these endocrine disruptors extend beyond embryonic development, altering sex-steroid physiology in exposed animals.

Pesticides and cancer.

Epidemiologic evidence on the relationship between chemical pesticides and cancer is reviewed. In animal studies, many pesticides are carcinogenic, (e.g., organochlorines, creosote, and sulfallate) while others (notably, the organochlorines DDT, chlordane, and lindane) are tumor promoters. Some contaminants in commercial pesticide formulations also may pose a carcinogenic risk. In humans, arsenic compounds and insecticides used occupationally have been classified as carcinogens by the International Agency for Research on Cancer. Human data, however, are limited by the small number of studies that evaluate individual pesticides. Epidemiologic studies, although sometimes contradictory, have linked phenoxy acid herbicides or contaminants in them with soft tissue sarcoma (STS) and malignant lymphoma; organochlorine insecticides are linked with STS, non-Hodgkin's lymphoma (NHL), leukemia, and, less consistently, with cancers of the lung and breast; organophosphorous compounds are linked with NHL and leukemia; and triazine herbicides with ovarian cancer. Few, if any, of these associations can be considered established and causal. Hence, further epidemiologic studies are needed with detailed exposure assessment for individual pesticides, taking into consideration work practices, use of protective equipment, and other measures to reduce risk.

Chlordane as a neurotoxin in humans.

To assay and profile chronic neurobehavioral impairment associated with chlordane exposure in symptomatic patients, consecutive evaluations of nine patients were done with sensitive neurophysiologic and neuropsychologic tests for neurobehavioral function. Their visual fields, balance, reaction time, blink, color discrimination, grip strength, cognitive function, recall, memory, and perceptual motor speed were tested, and mood states and frequencies of 35 symptoms were appraised. Prevalences of abnormality were compared test-by-test to predict values with confidence intervals, and mean values for the group were compared with reference values. Testing showed abnormal balance with eyes closed in 7, abnormal color discrimination in 6, verbal recall deficit in 5, and prolonged blink reflex latency, prolonged choice reaction time, and decreased Culture Fair scores in 4 each. Profile of Mood States score was elevated in 5. These observations suggest that chlordane causes protracted neurotoxicity.

Protracted neurotoxicity from chlordane sprayed to kill termites.

Over 250 adults and children were exposed to chlordane when the wooden building surfaces and soil around an apartment complex were sprayed in 1987. Two hundred-sixteen adults had neurobehavioral functions measured and completed questionnaires for symptom frequency, mood status, confounding factors, and medical, rheumatic, and respiratory disorders in 1994. Measurements included simple and choice reaction time, balance, blink reflex latency, color vision, cognitive, perceptual motor, memory, and recall functions. We analyzed 216 exposed and 174 referent adults. Age, educational level, weight, height, and gender ratio were similar for the exposed and referent groups. Performance of balance, reaction times, Culture Fair, digit symbol, verbal recall, and trail-making were significantly impaired in exposed persons compared to referents. Mood-state scores were elevated, as were the frequencies of respiratory, neurobehavioral, and rheumatic symptoms. In contrast, long-term memory function was similar in both groups, consistent with its status before exposure. There was no identified bias or confounding factors. Chlordane exposure was associated with protracted impairment of neurophysiological and psychological functions. The central nervous system is the most important target of chlorinated cyclodiene insecticides. Human exposure should be prohibited.

A method evaluating population risks from chemical exposure: a case study concerning prohibition of chlordane use in Japan.

The proposed method evaluating population risks from chemical exposure is based on estimation of the individual variabilities in the internal concentration of the chemical of concern and estimation of the magnitude of toxic effect caused at a given internal concentration. We assume a log-normal distribution for individual variability and propose loss of life expectancy (LLE) as a measure of the magnitude of toxic effects. We applied it to the evaluation of the governmental action of prohibiting the use of chlordane as a termiticide in Japan. Because the method is applicable to both carcinogenic and noncarcinogenic chemicals, the cancer risk due to chlordane and the noncancer risk due to chlorpyrifos, a major substitute, were evaluated and compared. The estimated values of risk represented in terms of LLE are 0.10 days for residents of untreated houses, 1.9 days for residents of treated houses, and 4.4 days for termite control workers when chlordane is used, and 0, 2.8, and 31 days when chlorpyrifos is used, respectively. From the result of the case study, we can see that the prohibition of chlordane is not necessarily effective in reducing risk.

Immune alterations in humans exposed to the termiticide technical chlordane.

Lymphocyte phenotype frequencies and in vitro functional assays were studied in 27 individuals who had been exposed to technical chlordane in their homes or at their places of work. A control group consisted of 118 individuals who were similar to the exposed group with respect to age and sex distribution, and who had not knowingly experienced exposure to technical chlordane, was chosen for study. A significantly increased frequency of cortical thymocytes in the circulation (CD1) (p less than .001) and a decreased frequency of the suppressor-inducer phenotype CD45RA/T4 (p less than .01) were noted in the exposed group. Both kappa and lambda light-chain frequencies were elevated (p less than .01). Proliferative responses to the three mitogens tested, PHA, CONA, PWM, and to allogeneic lymphocytes in the mixed-lymphocyte culture assay were significantly lower than in controls (p less than .01). Responses in assays of the natural killer function were not significantly different from those of controls, but Fc receptor-associated K cell function was significantly greater than responses in controls. Of 12 individuals tested for evidence of autoimmunity, 11 demonstrated some increased titer of a form of autoantibody. This cluster of significant findings demonstrates the emergence of aberrant peripheral T and B cell regulation and a potential for autoimmune activation, detectable up to 10 y after exposure to technical chlordane.