Serum Concentrations Of Organochlorine Pesticides Research Articles

Effect of Low-Dose Persistent Organic Pollutants on Mitochondrial Function: Human and in Vitro Evidence.

BackgroundChronic exposure to low-dose persistent organic pollutants (POPs) can induce mitochondrial dysfunction. This study evaluated the association between serum POP concentrations and oxygen consumption rate (OCR) as a marker of mitochondrial function in humans and in vitro cells.MethodsSerum concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in 323 adults. The OCRs of platelets and peripheral blood mononuclear cells (PBMCs) were assessed in 20 mL of fresh blood using a Seahorse XF analyzer. Additionally, the in vitro effects of Arochlor-1254, β-hexachlorocyclohexane, and p,p′-dichlorodiphenyltrichloroethane at concentrations of 0.1 pM to 100 nM were evaluated in human platelets, human PBMCs, and Jurkat T-cells.ResultsThe association between serum POP concentrations and OCR differed depending on the cell type. As serum OCP concentrations increased, basal platelet OCR levels decreased significantly; according to the OCP quintiles of summary measure, they were 8.6, 9.6, 8.2, 8.0, and 7.1 pmol/min/μg (P trend=0.005). Notably, the basal PBMC OCR levels decreased remarkably as the serum PCB concentration increased. PBMC OCR levels were 46.5, 34.3, 29.1, 16.5, and 13.1 pmol/min/μg according to the PCB quintiles of summary measure (P trend <0.001), and this inverse association was consistently observed in all subgroups stratified by age, sex, obesity, type 2 diabetes mellitus, and hypertension, respectively. In vitro experimental studies have also demonstrated that chronic exposure to low-dose POPs could decrease OCR levels.ConclusionThe findings from human and in vitro studies suggest that chronic exposure to low-dose POPs can induce mitochondrial dysfunction by impairing oxidative phosphorylation.

Serum concentrations of organochlorine pesticides, biomarkers of oxidative stress, and risk of breast cancer

Studies have documented that exposure to organochlorine pesticides (OCPs) is linked with breast cancer, but the underlying biological mechanisms are still unknown. This study included 313 women diagnosed with breast cancer and 313 controls in Wuhan, China, and measured 18 OCPs in serum and 3 oxidative stress biomarkers in urine. Multivariable adjusted regression models were used to evaluate the associations among OCPs, oxidative stress biomarkers, and breast cancer. The mediating effect of oxidative stress was assessed by mediation analysis. We observed that most OCPs were positively associated with risk of breast cancer (all FDR-P values < 0.05 or 0.10). Moreover, we found that p,p'-DDT, p,p'-DDD, dieldrin, heptachlor, and heptachlor epoxide were positively associated with 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA) and 8-iso-prostaglandin F2α (8-isoPGF2α), which in turn were positively associated with risk of breast cancer. Mediation analysis indicated that HNE-MA and 8-isoPGF2ɑ mediated the positive associations between these OCPs and risk of breast cancer, with mediating proportion ranging from 6.23% to 19.9%. Our results suggest that lipid peroxidation may mediate the positive associations between OCP exposures and risk of breast cancer.

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

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

Maternal and umbilical cord blood serum concentrations of organochlorine pesticides and investigation of possible effects on newborn

ABSTRACT Studies have shown the negative effects of organochlorine pesticide (OCP) exposure on humans, but few studies focus on the transmission of OCPs to the foetus during pregnancy and the effects of prenatal exposure on the newborn. In this study, maternal and cord blood samples were collected at deliveries and the prenatal exposures of OCPs were investigated. OCPs, analysed in the samples, were hexachlorobenzene (HCB), p,p’dichlorodiphenyldichloroethylene (p,p’DDE), o,p′dichlorodiphenyltrichloroethane (o,p’DDT) and p,p′dichlorodiphenyltrichloroethane (p,p′DDT). A statistically significant difference of OCPs concentration between the cord and maternal blood was not observed (respectively; p = 0.372; 0.441; 0.379; 0.611). In other words, it was found that OCPs in mothers were transferred to the newborns through cord blood. Besides, the effects of OCPs exposure on newborns were investigated and the method of delivery was marginally associated with o,p’-DDT concentration. Maternal OCPs residue levels measured in this study were positively correlated with concentrations measured in the umbilical cord blood suggesting that these OCPs were transferred to the foetus.

Can Habitual Exercise Help Reduce Serum Concentrations of Lipophilic Chemical Mixtures? Association between Physical Activity and Persistent Organic Pollutants.

BackgroundLow-dose persistent organic pollutants (POPs), especially organochlorine pesticides (OCPs), have emerged as a new risk factor of many chronic diseases. As serum concentrations of POPs in humans are mainly determined by both their release from adipose tissue to circulation and their elimination from circulation, management of these internal pathways may be important in controlling the serum concentrations of POPs. As habitual physical activity can increase the elimination of POPs from circulation, we evaluated whether chronic physical activity is related to low serum POP concentrations.MethodsA cross-sectional study of 1,850 healthy adults (age ≥20 years) without cardio-metabolic diseases who participated in the U.S. National Health and Nutrition Examination Survey 1999 to 2004 was conducted. Information on moderate or vigorous leisure-time physical activity was obtained based on questionnaires. Serum concentrations of OCPs and polychlorinated biphenyls were investigated as typical POPs.ResultsSerum concentrations of OCPs among physically active subjects were significantly lower than those among physically inactive subjects (312.8 ng/g lipid vs. 538.0 ng/g lipid, P<0.001). This difference was maintained after adjustment for potential confounders. When analyses were restricted to physically active subjects, there were small decreases in the serum concentrations of OCPs with increasing duration of physical activity, showing a curvilinear relationship over the whole range of physical activity (Pquadratic <0.001). In analyses stratified by age, sex, body mass index, and smoking status, a strong inverse association was similarly observed among all subgroups.ConclusionPhysical activity may assist in decreasing serum concentrations of lipophilic chemical mixtures such as OCPs.

Prediagnostic serum concentrations of organochlorine pesticides and non-Hodgkin lymphoma: A nested case–control study in the Norwegian Janus Serum Bank Cohort

BackgroundMuch of the marked increase in incidence of non-Hodgkin lymphoma (NHL) over the past few decades remains unexplained. Organochlorines, including organochlorine pesticides (OCPs), have been implicated as possible contributors to the increase, but the evidence is inconsistent. ObjectivesTo investigate the relation between pre-diagnostic levels of OCPs and risk of NHL in a case-control study nested within the population-based Janus Serum Bank Cohort in Norway. MethodsPrediagnostic concentrations of 11 OCPs or OCP metabolites were measured in baseline blood samples collected between 1972 and 1978 from 190 cases and 190 controls matched on sex, county, age at blood draw, and date of blood draw. We conducted conditional logistic regression to estimate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) for each quartile of lipid-corrected OCP/metabolite relative to the lowest quartile. ResultsWe observed non-significantly elevated ORs across quartiles of β-hexachlorocyclohexane compared to the lowest quartile (OR range: 1.40–1.82) although with no apparent monotonic exposure-response relationship. We also found an inverse association between risk of NHL and o,p'-DDT (OR for Q4 vs. Q1 = 0.44, 95% CI: 0.19, 1.01; p-trend = 0.05). In analyses stratified by age at blood collection and duration of follow-up, several other analytes, primarily chlordane-related compounds, showed inverse associations among younger participants or those with longer follow-up time between blood draw and NHL diagnosis. ConclusionsWe found only limited evidence of positive association between selected OCPs and development of NHL.

Is dietary macronutrient intake associated with serum concentrations of organochlorine pesticides in humans?

In the general population, chronic exposure to low-dose persistent organic pollutants (POPs), particularly organochlorine pesticides (OCPs), has been recently linked to many chronic diseases. Widespread contamination of the food chain and human adipose tissue has made avoiding exposure to these chemicals impossible; thus, alternative strategies for decreasing the chemical burden must be investigated. Recently, macronutrient intake was found to significantly modify the toxicokinetics of POPs in animal experimental studies. Thus, we evaluated whether macronutrient intake was related to serum concentrations of OCPs in healthy adults without cardio-metabolic diseases. Subjects included 1,764 adults, aged 20 years or above, who participated in the National Health and Nutrition Examination Survey 1999–2004. Macronutrient intake was assessed based on a 24-h dietary recall interview. Six individual OCPs commonly detected among the general population were evaluated as markers of OCPs and other coexisting lipophilic chemicals stored in adipose tissue and released into circulation. High fat intake was associated with lower concentrations of OCPs, while high carbohydrate intake showed the opposite result. When three types of fats were individually evaluated, both saturated fatty acids and monounsaturated fatty acids, but not polyunsaturated fatty acids, were inversely associated with serum concentrations of OCPs. Adjustment for possible confounders did not change the results. When stratified by age, gender, body mass index, and physical activity, these associations were similar in most subgroups. Thus, similar to the findings observed in animal experimental studies, a moderate-fat diet with low carbohydrate intake was related to low serum concentrations of OCPs in humans. Although these findings need to be replicated, changing dietary macronutrient intake can be investigated as a practical strategy for dealing with unavoidable lipophilic chemical mixtures such as OCPs in modern society.

Low-dose persistent organic pollutants and mitochondrial dysfunction in humans

TPS 634: Health effects of pops, voc and other chemicals, Johan Friso Foyer, Floor 1, August 27, 2019, 3:00 PM - 4:30 PM Background/Aim: Declining mitochondrial function, reflected by diminished electron transport chain activity, is related to many common chronic diseases. However, the risk factors of mitochondrial dysfunction are largely unknown. Recently, chronic exposure to low-dose environmental chemicals has been suspected to induce mitochondrial dysfunction in in vitro and in vivo settings. We evaluated the relationship between serum concentrations of lipophilic chemical mixtures and mitochondrial function in an apparently healthy population. Methods: Serum concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in 248 Korean adults aged 30-64 years. Platelet oxygen consumption rates (OCRs), measured using the Seahorse XF Analyzer was used as a biomarker of mitochondrial function in 20-ml samples of fresh peripheral blood. Results: Mean OCR decreased significantly with increasing serum concentrations of OCPs. Across quartiles of summary measure of OCPs, mean OCRs were 12.4, 11.2, 9.0, and 8.5 (P trend<0.01). When the last quartile of summary measure of OCPs was further categorized according to 90%- and 95%-cutoff points, the linear association became stronger. Similarly, this linear relationship was observed in subgroups stratified according to age, sex, and body mass index. PCBs showed much weaker associations than OCPs. Conclusions: Considering the current human, in vitro, and in-vivo evidence, we suggest that mitochondrial dysfunction may be a key mechanism that links chronic exposure to low-dose chemical mixtures to common chronic diseases, such as diabetes or dementia. (□ Acknowledgement: This work was supported by the Korea Ministry of Environment (MOE) as the Environmental Health Action Program (2016001370002).)

Association of colorectal polyps and cancer with low-dose persistent organic pollutants: A case-control study.

BackgroundLow-dose persistent organic pollutants (POPs) have recently been linked to immunosenescence, a key mechanism in carcinogenesis, as well as many aging-related chronic diseases. Since feces are the main excretion route of POPs, the large intestine is a potential target organ for these pollutants. We performed a case-control study to evaluate whether exposure to low-dose POPs is related to the risk of colorectal polyps and cancer.MethodsA total of 277 participants were recruited from one hospital: 99 cancer patients, 102 polyp patients, and 76 control subjects. As typical examples of POPs, we measured the serum concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs).ResultsAcross the tertiles of the summary measure of POPs, the adjusted odds ratios (ORs) of colorectal polyps and cancer were 2.8 (1.2–6.8) (Ptrend = 0.01) and 3.0 (1.0–8.8) (Ptrend = 0.02), respectively, for subjects in the highest tertile. When OCPs and PCBs were analyzed separately, OCPs were linked to an increased risk of both polyps and cancer; the adjusted ORs were 2.3 (0.9–5.7) (Ptrend = 0.05) for polyps and 3.6 (1.1–11.8) (Ptrend< 0.01) for cancer. However, PCBs were only significantly associated with a high risk of polyps but not cancer; the adjusted OR was 2.8 (1.2–6.6) (Ptrend = 0.01).ConclusionChronic exposure to low-dose POPs may be associated with an increased risk of colorectal polyps and cancer. Our findings suggest the carcinogenic potential of strong lipophilic chemical mixtures such as POPs which are accumulated in adipose tissue, released to circulation, and eliminated through feces.

Association of low-dose exposure to persistent organic pollutants with E-cadherin promoter methylation in healthy Koreans

Background: Persistent organic pollutants (POPs), despite their considerably low levels in humans, are an increasing concern for the general populations given their various adverse health problems, including metabolic and carcinogenic effects. DNA methylation deregulation is thought to be a key mechanism in the development of human chronic diseases including cancer.Methods: In an attempt to identify biomarkers monitoring low-dose exposure and hazard, we explored whether organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) may influence the methylation of tumour suppressor gene E-cadherin (CDH1) using peripheral blood cells from 364 healthy Korean subjects.Results: CDH1 methylation was observed in 78.3% of study subjects. Serum concentrations of OCPs or PCBs compounds were higher in CDH1 methylation-positive subjects than in methylation-negative ones. After adjusting for various covariates, the odds ratio of CDH1 methylation of the summary measure of PCBs were 1.0, 2.5 (95% confidence interval: 1.2–5.3), 3.6 (1.6–8.1), 3.6 (1.4–8.6), and 2.5 (1.1–5.7) across quintiles of PCBs (Ptrend = 0.01). The values of OCPs were 1.0, 0.9, 1.2, 2.4 (1.0–5.9), and 1.7 (Ptrend = 0.05).Conclusions: In this exploratory study with a small sample, CDH1 methylation might be served as the epigenetic biomarker associated with POPs exposure and adverse health effect.

Association of serum organochlorine pesticides concentrations with reproductive hormone levels and polycystic ovary syndrome in a Chinese population

To investigate the serum concentrations of organochlorine pesticides (OCPs) in patients with polycystic ovary syndrome (PCOS), a total of 178 women were studied. The concentrations of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) in serum were determined using Gas Chromatography Mass-Mass Spectrometer. No differences with statistical significance in the mean HCH, p,p′-DDD, p,p’-DDE concentrations were observed between the patients with PCOS and the control group. Serum p,p′-DDT (P = 0.016) and o,p′-DDT (P = 0.000) levels were significantly higher in patients with PCOS compared with the control group. The results of the association between OCPs levels and hormone levels indicated that o,p′-DDT may play a role in the pathogenesis of PCOS by affecting hormones levels. Further trials should be investigated with the findings in this study to obtain new pathogenesis of PCOS.

Can Inconsistent Association between Hypertension and Cognition in Elders be Explained by Levels of Organochlorine Pesticides?

The relation between hypertension and cognition in elders remains unclear, and studies on the effect of antihypertensive drugs on cognition have demonstrated conflicting results. This study was performed to evaluate if the association between hypertension and cognition in elders differed depending on serum concentrations of organochlorine (OC) pesticides, common neurotoxic chemicals. Participants were 644 elders aged 60–85 years who participated in the National Health and Nutrition Examination Survey 1999–2002 and were able to complete a cognitive test. We selected 6 OC pesticides that were commonly detected in the elderly. Cognition was assessed by the Digit Symbol Substitution Test (DSST), a relevant tool for evaluating hypertension-related cognitive function, and low cognition was defined by the DSST score < 25th percentile. When OC pesticides were not considered in the analyses, elders with hypertension had about 1.7 times higher risk of low cognition than those without hypertension. However, in analyses stratified by serum concentrations of OC pesticides, the associations between hypertension and low cognition were stronger the higher the serum concentrations of p,p’-DDT, p,p’-DDE, β-hexachlorocyclohexane, and trans-nonachlor increased. Among elders in the 3rd tertile of these pesticides, adjusted odds ratios were from 2.5 to 3.5. In contrast, hypertension was not clearly associated with the risk of low cognition in elders in the 1st tertile of these pesticides. Similar patterns were observed for the continuous DSST score dependent variable. The difference in the association between hypertension and DSST scores according to the levels of OC pesticides suggest a key role of OC pesticides in the development of hypertension-related cognitive impairment and may help to identify hypertensive elders who are at a high risk of cognitive impairment.

Greater cognitive decline with aging among elders with high serum concentrations of organochlorine pesticides.

Although cognitive decline is very common in elders, age-related cognitive decline substantially differs among elders and the determinants of the differences in age-related cognitive decline are unclear. We investigated our hypothesis that the association between age and cognition was stronger in those with higher serum concentrations of organochlorine (OC) pesticides, common persistent and strongly lipophilic neurotoxic chemicals. Participants were 644 elders aged 60-85, participating in the National Health and Nutrition Examination Survey 1999-2002. Six OC pesticides (p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodipenyldichloroethylene (DDE), β-hexachlorocyclohexane, trans-nonachlor, oxychlordane, and heptachlor epoxide) were evaluated. “Lower cognitive function” was defined as having a low Digit-Symbol Substitution Test (DSST) score (<25th percentile of DSST score, cutpoint 28 symbols substituted). Higher levels of β-hexachlorocyclohexane, trans-nonachlor, oxychlordane, and heptachlor epoxide modified the associations between age and lower cognitive function (Pinteraction<0.01, 0.03, <0.01, and 0.02, respectively). Elders in the 3rd tertile of these chemicals demonstrated a greater risk of lower cognitive function with aging, compared to those in the combined 1st and 2nd tertiles. Among those with highest OC pesticides (3rd tertile), the odds ratio for the risk of lower cognitive function was about 6 to 11 for the highest quintile of age (80-85 years) vs. the first quintile of age (60-63 years), while the association between age and lower cognitive function became flatter in those with lower OC pesticides (combined 1st and 2nd tertiles). Both DDT and DDE showed no interaction, with lower DSST scores for higher age irrespective of serum concentrations of DDT or DDE. Even though DSST score measures only one aspect of cognition, several OC pesticides modified aging-related prevalence of low cognitive score, a finding which should be evaluated in prospective studies.

Prepubertal Serum Concentrations of Organochlorine Pesticides and Age at Sexual Maturity in Russian Boys.

BackgroundFew human studies have evaluated the impact of childhood exposure to organochlorine pesticides (OCP) on pubertal development.ObjectiveWe evaluated associations of serum OCP concentrations [hexachlorobenzene (HCB), β-hexachlorocyclohexane (βHCH), and p,p-dichlorodiphenyldichloroethylene (p,p´-DDE)] with age at attainment of sexual maturity among boys.MethodsFrom 2003 through 2005, 350 8- to 9-year-old boys from Chapaevsk, Russia, with measured OCPs were enrolled and followed annually for 8 years. We used multivariable interval-censored models to evaluate associations of OCPs (quartiles) with three physician-assessed measures of sexual maturity: Tanner stage 5 for genitalia growth, Tanner stage 5 for pubic hair growth, or testicular volume (TV) ≥ 20 mL in either testis.ResultsIn adjusted models, boys with higher HCB concentrations achieved sexual maturity reflected by TV ≥ 20 mL a mean of 3.1 months (95% CI: –1.7, 7.8), 5.3 months (95% CI: 0.6, 10.1), and 5.0 months (95% CI: 0.2, 9.8) later for quartiles Q2, Q3, and Q4, respectively, compared with Q1 (p trend = 0.04). Tanner stage 5 for genitalia growth was attained a mean of 2.2 months (95% CI: –3.1, 7.5), 5.7 months (95% CI: 0.4, 11.0), and 3.7 months (95% CI: –1.7, 9.1) later for quartiles Q2, Q3, and Q4, respectively, of βHCH compared with Q1 (p trend = 0.09). Tanner stage 5 for pubic hair growth occurred 6–9 months later on average for boys in the highest versus lowest quartile for HCB (p trend < 0.001), βHCH (trend p = 0.01), and p,p´-DDE (p trend = 0.04). No associations were observed between p,p´-DDE and Tanner stage 5 for genitalia growth or TV ≥ 20 mL.Conclusions and relevanceHigher prepubertal serum HCB and βHCH concentrations were associated with a later age at attainment of sexual maturity. Only the highest quartile of serum p,p´-DDE was associated with later pubic hair maturation.CitationLam T, Williams PL, Lee MM, Korrick SA, Birnbaum LS, Burns JS, Sergeyev O, Revich B, Altshul LM, Patterson DG Jr, Hauser R. 2015. Prepubertal serum concentrations of organochlorine pesticides and age at sexual maturity in Russian boys. Environ Health Perspect 123:1216–1221; http://dx.doi.org/10.1289/ehp.1409022

Risk of female breast cancer and serum concentrations of organochlorine pesticides and polychlorinated biphenyls: A case–control study in Tunisia

The aim of this study was to investigate the association between serum concentrations of a group of organochlorine pesticides/polychlorinated biphenyls with xenoestrogenic potential and the risk of breast cancer in a female population from Tunisia.The relationship between serum levels of the pollutants and the risk of cancer was assessed using logistic regression analyses. In the unadjusted models, β-hexachlorocyclohexane (β-HCH), hexachlorobenzene, heptachlor, polychlorinated biphenyl congeners 138, 153, and 180, and p,p′-dichlorodiphenyldichloroethylene (p,p′-DDE) were positively associated with breast cancer risk. However, when the models were further adjusted for the selected covariates, only β-HCH and p,p′-DDE remained statistically significant, and heptachlor was borderline significant. In addition, analyses using POP concentration tertiles corroborated a positive dose–response relationship that was significant for p,p′-DDE (p-trend=0.020) and borderline significant for heptachlor (p-trend=0.078). A similar trend was also confirmed for β-HCH, in which concentrations≥limit of detection were positively associated with breast cancer risk (vs. concentrations<limit of detection, OR=3.44, p<0.05). Finally, the relative influence of each chemical in the presence of the others was assessed by entering the three chemicals in a single model with all covariates, and only β-HCH remained positively associated with the risk of cancer (OR:1.18, 95%CI: 1.05–1.34).Our findings suggest a potential association between exposure to at least one organochlorine pesticide and breast cancer risk. However, our results should be interpreted with caution, and further research is warranted to confirm these findings.

Associations between organochlorine pesticides and cognition in U.S. elders: National Health and Nutrition Examination Survey 1999–2002

There is limited evidence about whether background exposure to organochlorine pesticides is related to impairment of cognitive function in general populations. This study was performed to investigate cross-sectional associations between serum concentrations of organochlorine pesticides and cognitive function, a predictor of dementia, among U.S. elders without overt dementia. Study subjects were 644 elders aged 60–85, participating in the National Health and Nutrition Examination Survey 1999–2002. We selected 6 organochlorine pesticides (p,p′-dichlorodiphenyltrichloroethane (DDT), p,p′-dichlorodiphenyldichloroethylene (DDE), trans-nonachlor, oxychlordane, heptachlor epoxide, and β-hexachlorocyclohexane) which were commonly detected in current general population. Cognitive function was assessed with the Digit-Symbol Substitution Test. All 6 compounds showed statistically significant or marginally significant inverse associations with cognitive score after adjusting for covariates including education levels. The strongest association was observed with p,p′-DDT. With the outcome of low cognitive score defined as <25th percentile, elders in the highest quartile of p,p′-DDT, p,p′-DDE, and β-hexachlorocyclohexane had 2 to 3 times higher risks than those in the lowest quartile. In particular, when their concentrations were further divided with the cutoff points of 90th and 95th percentiles, p,p′-DDT in the highest 5th percentile showed 6.5 (95% confidence interval: 2.6–16.3) times higher risk of low cognitive score. On the other hand, non-persistent pesticides like organophosphates or pyrethroid showed little association with this cognitive score. The potential role of background exposure to organochlorine pesticides in the development of dementia should be explored in future prospective studies and in-vitro/in-vivo experimental studies.

Serum concentrations of organochlorine pesticides associated with diabetes and obesity in Northern Benin (West Africa)

Aim: Diabetes rising prevalence is of great concern in Africa because of its socio-economic impacts in a context of limited access to health care. The inappropriate use of pesticides may add to the burden of diabetes in Africa. The present study was carried out in a cotton producing area of Benin in order to assess the relationship between the highest prevalence of diabetes observed in the country and organochlorine pesticide (OCP) exposure. Methods: A case-control study was conducted in 2011. A sample of 106 subjects with diabetes and 106 non-diabetic controls were paired by age, gender, ethnicity and residential area. Personal and socioeconomic information, along with anthropometric measurements were collected. Blood samples were assayed for total lipids and 14 OCPs by gas-chromatography coupled with mass-spectrometry. Data were recorded for the four detectable OCPs: p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE), p,p’-dichlorodiphenyltrichloroethane (p,p’-DDT), β -hexachlorocyclohexane (β-HCH), and trans-nonachlor. Results: Serum levels of all four detected OCPs were consistently higher in diabetic subjects than in non-diabetic controls. The odds ratio of diabetes was nearly three-fold higher when comparing the third tertile of p,p’-DDE and p,p’-DDT and β-HCH levels with the first tertile, without adjustment for potential confounders. The association remained significant for p,p’-DDT (OR = 2.59; 95% CI: 1.17-5.42) and p,p’-DDE (OR = 2.11; 95% CI: 1.01-4.54) after adjusting for a family history of diabetes, abdominal obesity, and wealth index or education. Conclusion: Our data showed that exposure to p,p’-DDT and p,p’-DDE was associated with an increased risk of diabetes. These findings have major public health implications.

Serum concentrations of organochlorine pesticides &lt;i&gt;p,p´&lt;/i&gt;-DDE in adult Thai residents with background levels of exposure

In Thailand, DDT was banned for agriculture use in 1983 and for malaria vector control in 1999. However, contamination by DDT and its primary metabolite, p,p'-DDE remains serious environmental and human health concerns. The main focus of this study were i) to investigate serum concentrations of p,p'-DDE and p,p'-DDT as exposure biomarkers for potential adverse health effect in adult Thai residents and ii) to compare the associations of BMI, thyroid hormones, cholesterol, triglycerides and fasting blood sugar levels in human serum with the concentrations of these pesticides. In a total of 1,137 participants were measured blood serum for analyses of p,p'-DDE and p,p'-DDT. The geometric mean concentration (95% confidence interval) for serum total p,p'-DDE concentration was 1,539 (1,242-1,837) ng/g lipid and 1,547 (1,293-1,806) ng/g lipid in adult males and females, respectively. Furthermore, the total amount of serum p,p'-DDE concentration significantly correlated with plasma glucose levels. Neither p,p'-DDE nor p,p'-DDT was significantly associated with serum thyroid hormones levels. Additionally, the high p,p'-DDE/DDT ratio indicates that the exposure is due past rather than recent use of DDT.

Association between serum levels of organochlorine pesticides and sex hormones in adults living in a heavily contaminated area in Brazil

Several studies have investigated the effects of organochlorine (OC) pesticides on adverse reproductive outcomes. However, few previous studies explored their effects on sex hormones. To examine the association between serum concentrations of OC pesticides and levels of sex hormones in adult population in a rural area in Brazil heavily contaminated with these pesticides. A cross-sectional study with 304 men and 300 women was undertaken. Wet weight serum concentrations of 19 OC pesticides (dichloro-diphenyl-trichloroethane [DDT] and hexachlorocyclohexane [HCH], among others) were determined in all participants. Testosterone levels were obtained for men and estradiol, progesterone, prolactin, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) for women. Associations between OC pesticides and sex hormones were evaluated using linear regression models. Prevalence of women with non-physiological hyperprolactinemia was 4%. After adjusting for serum lipids and confounders, heptachlor and o,p'-DDT concentrations in men were associated with lower testosterone levels, while peri- and postmenopausal women (N=77) showed inverse associations between LH and hexachlorobenzene (HCB), p,p'-DDT, p,p'-DDD (dichloro-diphenyl-dichloroethane), endosulfan 1 and 2, aldrin and mirex, as well as between FSH and p,p'-DDD, endosulfan 1 and aldrin. Premenopausal women (N=210) did not show statistically significant associations between OC pesticides and sex hormones. Inverse associations between OC pesticide concentrations and testosterone in men and LH and FSH in peri-/postmenopausal women, together with the high proportion of women with elevated prolactin, suggest that these OC compounds may have triggered anti-androgenic effects in men and estrogenic effects in women in this population.

Persistent organic pollutants and hyperuricemia in the U.S. general population

BackgroundBackground exposure to persistent organic pollutants (POPs) has emerged as a new risk factor for metabolic syndrome (MetS), while hyperuricemia is associated with MetS through unclear mechanisms. ObjectiveWe examined cross-sectional data for consistency with the hypothesis that POPs are a common underlying risk factor of both MetS and hyperuricemia. MethodsWe evaluated associations of POPs with hyperuricemia in subjects aged ≥20 years in the population-based National Health and Nutrition Examination Survey (NHANES) 2003–2004. Sample size was n = 1331 for organochlorine (OC) pesticides and n = 1299 for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). ResultsAmong all subjects, the risk of hyperuricemia was higher for higher serum concentrations of OC pesticides, PCDDs, and dioxin-like PCBs. PCDFs and nondioxin-like PCBs did not show any clear trend. Adjusted odds ratios (ORs) for OC pesticides, PCDDs, and dioxin-like PCBs were 1.0, 2.4, 2.3, 3.0, and 2.5 (P trend = 0.05), 1.0, 1.6, 1.4, 2.1, and 2.5 (P trend = 0.01), and 1.0, 1.3, 1.4, 1.3, and 2.4 (P trend = 0.04). When we restricted the analyses to subjects without MetS, all these associations appeared to strengthen. ConclusionThis study is consistent with our hypothesis that the risk of hyperuricemia relates to background exposure to a mixture of POPs even among persons without MetS. There should be further research about whether avoiding exposure to POPs and otherwise decreasing body burden of POPs would be helpful to prevent or manage hyperuricemia or gout.