Display omitted
•Parabens are common preservatives that can interfere with the endocrine system.•Human exposure to parabens is ubiquitous.•Parabens were associated with metabolic syndrome among adult ...men.•Inverse associations were found with obesity, metabolic syndrome and HDL in women.•No associations with obesity or metabolic indicators were found in children.
Parabens are group of widely used preservative agents in the cosmetic, food, and pharmaceutical industries. They are estrogenic and anti-androgenic, and thus have the potential to alter the hormonal regulation of energy metabolism, and in turn affect obesity and metabolic health. Compared to obesity alone, having metabolic syndrome (a cluster of cardiometabolic risk factors) further increases the risk of cardiovascular disease, diabetes, and certain cancers. We examined whether exposure to parabens was associated with obesity, metabolic syndrome or its components among Canadians.
Methyl, ethyl, propyl, and butyl paraben concentrations were measured in the urine of 2,564 individuals participating in Cycle 4 (2014–2015) of the Canadian Health Measures Survey, a national biomonitoring survey. We assessed associations between specific gravity-corrected log10-transformed paraben concentrations and obesity, metabolic syndrome and its components (waist circumference, HDL cholesterol, triglycerides, fasting blood glucose and blood pressure) via Poisson regression with robust variance estimators for binary outcomes and via linear regression for outcomes expressed continuously. We stratified analyses by age (children aged 3 to 17 years vs. adults aged 18 years and older) and investigated the presence of effect modification by sex.
A 10-fold increase in propyl paraben concentration was associated with a 40% (95% CI: 3, 90) higher prevalence of metabolic syndrome among men, while ethyl paraben was associated with a 63% (95% CI: 2, 86) lower prevalence among women. Among women, methyl paraben was inversely associated with obesity, and methyl, propyl and ethyl parabens were associated with higher high density lipoprotein (HDL) cholesterol. No associations were observed among children.
This is the first study to report a positive association between parabens and metabolic syndrome in men. Protective associations among women previously reported for obesity were also observed for metabolic syndrome and HDL cholesterol. These results should be confirmed in longitudinal studies.
Pregnant women may be co-exposed to multiple insecticides in regions where both pyrethroids and dichlorodiphenyltrichloroethane (DDT) are used for indoor residual spraying (IRS) for malaria control. ...Despite the potential for adverse effects on offspring, there are few studies in areas where IRS is currently used and little is known about the effects of pyrethroids on children's health.
We investigated the relationship between concentrations of four urinary pyrethroid metabolites in urine and organochlorine pesticide concentrations in maternal blood collected near delivery on body weight and body composition among children ≤2 years old participating in the prospective South Africa VHEMBE birth cohort (N = 708). We used measurements of length/height and weight collected at 1 and 2 years of age to calculate body mass index (BMI)-for-age, weight-for-age, and weight-for-height z-scores based on World Health Organization standards. We fit separate single-pollutant mixed effects models for each exposure of interest and also stratified by sex. We also fit all analyte concentrations jointly by using a Bayesian kernel machine regression (BKMR) statistical method to assess variable importance of each analyte and to explore the potential for joint effects of the multiple exposures.
Single-pollutant linear mixed effects models showed that, among girls only, p,p′-DDT was associated with higher BMI-for-age (adjusted aβ = 0.22 95% CI: 0.10, 0.35; sex interaction p-value = 0.001), weight-for-height (aβ = 0.22 95% CI: 0.09, 0.34; sex interaction p-value = 0.002), and weight-for-age (aβ = 0.17 95% CI: 0.05, 0.29, sex interaction p-value = 0.01). Although single-pollutant models suggested that p,p′-DDT and dichlorodiphenyldichloroethylene (p,p′-DDE) were also associated with these outcomes in girls, p,p′-DDE was no longer associated in multi-pollutant models with BKMR. The pyrethroid metabolites cis-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylicacid (cis-DBCA) and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (trans-DCCA) were inversely related to BMI-for-age and weight-for-height overall; however, results suggested that weight-for-age and weight-for-height associations for trans-DCCA (sex interaction p-valueweight-for-age = 0.02; p-valueweight-for-height = 0.13) and cis-DCCA (sex interaction p-valueweight-for-age = 0.02; p-valueweight-for-height = 0.08) were strongest and most consistent in boys relative to girls. BKMR also revealed joint effects from the chemical mixture. For instance, with increased concentrations of p,p′-DDE, the negative exposure-response relationship for cis-DBCA on BMI-for-age became steeper.
Our single-pollutant and multi-pollutant model results show that maternal serum p,p′-DDT concentration was consistently and positively associated with body composition and body weight in young girls and that maternal urinary pyrethroid metabolite concentrations (particularly cis-DBCA and trans-DCCA) were negatively associated with body weight and body composition in young boys. Joint effects of the insecticide exposure mixture were also apparent, underscoring the importance of using advanced statistical methods to examine the health effects of chemical mixtures.
•p,p′-DDT was associated with higher body composition in girls only.•Pyrethroid metabolites were associated with lower body composition in boys.•Insecticide exposure associations were influenced by the overall exposure mixture.
Many studies report the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. We aimed to synthesize seroprevalence data to better estimate the level and ...distribution of SARS-CoV-2 infection, identify high-risk groups, and inform public health decision making.
In this systematic review and meta-analysis, we searched publication databases, preprint servers, and grey literature sources for seroepidemiological study reports, from January 1, 2020 to December 31, 2020. We included studies that reported a sample size, study date, location, and seroprevalence estimate. We corrected estimates for imperfect test accuracy with Bayesian measurement error models, conducted meta-analysis to identify demographic differences in the prevalence of SARS-CoV-2 antibodies, and meta-regression to identify study-level factors associated with seroprevalence. We compared region-specific seroprevalence data to confirmed cumulative incidence. PROSPERO: CRD42020183634.
We identified 968 seroprevalence studies including 9.3 million participants in 74 countries. There were 472 studies (49%) at low or moderate risk of bias. Seroprevalence was low in the general population (median 4.5%, IQR 2.4-8.4%); however, it varied widely in specific populations from low (0.6% perinatal) to high (59% persons in assisted living and long-term care facilities). Median seroprevalence also varied by Global Burden of Disease region, from 0.6% in Southeast Asia, East Asia and Oceania to 19.5% in Sub-Saharan Africa (p<0.001). National studies had lower seroprevalence estimates than regional and local studies (p<0.001). Compared to Caucasian persons, Black persons (prevalence ratio RR 3.37, 95% CI 2.64-4.29), Asian persons (RR 2.47, 95% CI 1.96-3.11), Indigenous persons (RR 5.47, 95% CI 1.01-32.6), and multi-racial persons (RR 1.89, 95% CI 1.60-2.24) were more likely to be seropositive. Seroprevalence was higher among people ages 18-64 compared to 65 and over (RR 1.27, 95% CI 1.11-1.45). Health care workers in contact with infected persons had a 2.10 times (95% CI 1.28-3.44) higher risk compared to health care workers without known contact. There was no difference in seroprevalence between sex groups. Seroprevalence estimates from national studies were a median 18.1 times (IQR 5.9-38.7) higher than the corresponding SARS-CoV-2 cumulative incidence, but there was large variation between Global Burden of Disease regions from 6.7 in South Asia to 602.5 in Sub-Saharan Africa. Notable methodological limitations of serosurveys included absent reporting of test information, no statistical correction for demographics or test sensitivity and specificity, use of non-probability sampling and use of non-representative sample frames.
Most of the population remains susceptible to SARS-CoV-2 infection. Public health measures must be improved to protect disproportionately affected groups, including racial and ethnic minorities, until vaccine-derived herd immunity is achieved. Improvements in serosurvey design and reporting are needed for ongoing monitoring of infection prevalence and the pandemic response.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Indoor residual spraying (IRS) of insecticides, conducted in low- and middle-income countries to control malaria, may result in high exposure to dichlorodiphenyltrichloroethane (DDT), its breakdown ...product dichlorodiphenyldichloroethylene (DDE), or pyrethroids. Animal studies suggest
exposure to these chemicals may increase childhood infection frequency.
We investigated associations between maternal DDT/E and pyrethroid metabolite concentration and child infection associations in an IRS setting in which susceptibility factors are common and infections are leading causes of child morbidity and mortality.
Using gas chromatography-mass spectrometry, we measured serum DDT/E and urinary pyrethroid metabolite concentrations in peripartum samples from 674 women participating in the Venda Health Examination of Mother, Babies and their Environment (VHEMBE) study. Counts of persistent child fevers, otitis media, and severe sore throat between 1 and 2 y of age were ascertained from maternal interviews. Associations between DDT/E and pyrethroid metabolite concentrations and infections were estimated using zero-inflated Poisson regression. We estimated relative excess risks due to interaction (RERI) with poverty, maternal energy intake, and maternal HIV status.
Concentrations of DDT/E, particularly
-DDE, were associated with higher rates of persistent fevers IRR=1.21 (95% CI: 1.01, 1.46), for a 10-fold increase in
-DDE). This association was stronger among children from households below versus above the South African food poverty line IRR=1.31 (95% CI: 1.08, 1.59) vs. IRR=0.93 (95% CI: 0.69, 1.25), respectively and for children whose mothers had insufficient versus sufficient caloric intake during pregnancy IRR=1.30 (95% CI: 1.07, 1.58) vs. IRR=0.96 (95% CI: 0.72, 1.28), respectively.
IRS insecticide exposure may increase childhood infection rates. This was particularly apparent among children from poorer households or whose mothers had low energy intake during pregnancy. https://doi.org/10.1289/EHP2657.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Display omitted
•Fluoride may disrupt thyroid function in pregnant women.•Fluoride exposure was associated with alterations in maternal thyroid hormone levels.•Urinary fluoride was associated with ...significantly higher TSH among those pregnant with females.•Adjustment for maternal iodine status did not change the results.
Fluoride exposure may increase the risk of hypothyroidism, but results from previous studies are inconsistent at low-level fluoride exposure (i.e., ≤0.7 mg/L). Human studies of fluoride and thyroid hormone levels in pregnancy are scarce.
We examined associations between fluoride exposure and maternal thyroid hormone levels in a Canadian pregnancy cohort, with consideration for fetal sex-specific effects.
We measured fluoride concentrations in drinking water and spot urine samples collected during each trimester from 1876 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. We also measured maternal thyroid stimulating hormone (TSH), free thyroxine (FT4), and total thyroxine (TT4) levels during the first trimester of pregnancy. We used linear and non-linear regression models to estimate associations between fluoride exposure and levels of TSH, FT4, and TT4. We explored effect modification by fetal sex and considered maternal iodine status as a potential confounder.
A 1 mg/L increase in urinary fluoride was associated with a 0.30 (95 %CI: 0.08, 0.51) logarithmic unit (i.e., 35.0 %) increase in TSH among women pregnant with females, but not males (B = 0.02; 95 %CI: −0.16, 0.19). Relative to women with urinary fluoride concentrations in the first quartile (0.05–0.32 mg/L), those with levels in the third quartile (0.49–0.75 mg/L) had higher FT4 and TT4 (i.e., inverted J-shaped associations), but the association was not statistically significant after adjustment for covariates (p = 0.06). Water fluoride concentration showed a U-shaped association with maternal FT4, whereby women with water fluoride concentrations in the second (0.13–0.52 mg/L) and third (0.52–0.62 mg/L) quartiles had significantly lower FT4 compared to those with levels in the first quartile (0.04–0.13 mg/L). Adjustment for maternal iodine status did not change the results.
Fluoride exposure was associated with alterations in maternal thyroid hormone levels, the magnitude of which appeared to vary by fetal sex. Given the importance of maternal thyroid hormones for fetal neurodevelopment, replication of findings is warranted.
Background: Human exposure to polybrominated diphenyl ether (PBDE) flame retardants has increased exponentially over the last three decades. Animal and human studies suggest that PBDEs may disrupt ...thyroid function. Although thyroid hormone (TH) of maternal origin plays an essential role in normal fetal brain development, there is a paucity of human data regarding associations between exposure to PBDEs and maternal TH levels during pregnancy. Objectives: Our goal was to determine whether PBDE serum concentrations are associated with TH levels in pregnant women. Methods: We measured the concentration of 10 PBDE congeners, free thyroxine (T₄), total T₄, and thyroid-stimulating hormone (TSH) in 270 pregnant women around the 27th week of gestation. Results: Serum concentrations of individual PBDE congeners with detection frequencies > 50% (BDEs 28, 47, 99, 100, and 153) and their sum (ΣPBDEs) were inversely associated with TSH levels. Decreases in TSH ranged between 10.9% 95% confidence interval (CI), -20.6 to 0.0 and 18.7% (95% CI, -29.2 to -4.5) for every 10-fold increase in the concentration of individual congeners. Odds of subclinical hyperthyroidism (low TSH but normal T₄) were also significantly elevated in participants in the highest quartile of ΣPBDEs and BDEs 100 and 153 relative to those in the first quartile. Associations between PBDEs and free and total T₄ were not statistically significant. Results were not substantially altered after the removal of outliers and were independent of the method used to adjust for blood lipid levels and to express ΣPBDEs. Conclusions: Results suggest that exposure to PBDEs is associated with lower TSH during pregnancy. Findings may have implications for maternal health and fetal development.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Background: Exposure to polybrominated diphenyl ether (PBDE) flame retardants is widespread, with 97% of Americans having detectable levels. Although PBDEs have been associated with reproductive and ...hormonal effects in animals, no human studies have examined their association with fertility. Objectives: This study was designed to determine whether maternal concentrations of PBDEs in serum collected during pregnancy are associated with time to pregnancy and menstrual cycle characteristics. Methods: Pregnant women (n = 223) living in a low-income, predominantly Mexican-immigrant community in California were interviewed to determine how many months they took to become pregnant. Blood samples were collected and analyzed for PBDEs. PBDE concentrations were lipid adjusted and log₁₀ transformed. Analyses were limited to PBDE congeners detected in > 75% of the population (BDEs 47, 99, 100, 153). Cox proportional hazards models modified for discrete time were used to obtain fecundability odds ratios (fORs) for the association of PBDEs and time to pregnancy. Results: We detected all four congeners in > 97% of women. Increasing levels of BDEs 47, 99, 100, 153 and the sum of these four congeners were all associated with longer time to pregnancy. We observed significantly reduced fORs for BDE-100 adjusted fOR = 0.6; 95% confidence interval (CI), 0.4–0.9, BDE-153 (adjusted fOR = 0.5; 95% CI, 0.3–0.8), and the sum of the four congeners (adjusted fOR = 0.7; 95% CI, 0.5–1.0). PBDEs were not associated with menstrual cycle characteristics. Conclusions: We found significant decreases in fecundability associated with PBDE exposure in women. Future studies are needed to replicate and confirm this finding.
Although indoor residual spraying (IRS) with dichlorodiphenyltrichloroethane (DDT) and pyrethroids effectively controls malaria, it potentially increases human exposure to these insecticides. ...Previous studies suggest that prenatal exposure to these insecticides may impact human neurodevelopment.
We aimed to estimate the effects of maternal insecticide exposure and neurodevelopment of toddlers living in a malaria-endemic region currently using IRS.
The Venda Health Examination of Mothers, Babies and their Environment (VHEMBE) is a birth cohort of 752 mother-child pairs in Limpopo, South Africa. We measured maternal exposure to DDT and its breakdown product, dichlorodiphenyldichloroethylene (DDE), in maternal serum, and measured pyrethroid metabolites in maternal urine. We assessed children's neurodevelopment at 1 and 2 y of age using the Bayley Scales of Infant Development, third edition (BSID-III), and examined associations with maternal exposure.
DDT and DDE were not associated with significantly lower scores for any BSID-III scale. In contrast, each 10-fold increase in
-DCCA,
-DCCA, and 3-phenoxybenzoic acid were associated, respectively, with a -0.63 (95% CI: -1.14, -0.12), -0.48 (95% CI: -0.92, -0.05), and -0.58 (-1.11, -0.06) decrement in Social-Emotional scores at 1 y of age. In addition, each 10-fold increase in maternal
-DBCA levels was associated with significant decrements at 2 y of age in Language Composite scores and Expressive Communication scores β=-1.74 (95% CI: -3.34, -0.13) and β=-0.40 (95% CI: -0.77, -0.04), respectively, for a 10-fold increase. Significant differences by sex were estimated for pyrethroid metabolites and motor function scores at 2 y of age, with higher scores for boys and lower scores for girls.
Prenatal exposure to pyrethroids may be associated at 1 y of age with poorer social-emotional development. At 2 y of age, poorer language development was observed with higher prenatal pyrethroid levels. Considering the widespread use of pyrethroids, these findings deserve further investigation. https://doi.org/10.1289/EHP2129.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Indoor Residual Spraying (IRS), the application of insecticides on the inside walls of dwellings, is used by 84 countries for malaria control. Although effective in preventing malaria, this practice ...results in elevated insecticide exposure to >100 million people, most of whom are Africans. Pyrethroid insecticides and dichlorodiphenyl trichloroethane (DDT) are currently used for IRS. Animal and in vitro studies suggest that pyrethroids and DDT interfere with thyroid hormone homeostasis but human studies are inconsistent and no prior study has investigated this question in a population residing in an area where IRS is conducted. Our objective was thus to evaluate whether prenatal exposure to pyrethroids, DDT or DDT's breakdown product dichlorodiphenyl dichloroethylene (DDE) is associated with altered thyroid hormone levels among neonates from Limpopo, South Africa, where pyrethroids and DDT are used annually to control malaria. We measured serum DDT/E and urinary pyrethroid metabolite concentrations in maternal peripartum samples from 717 women participating in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE), a birth cohort study conducted in Limpopo's Vhembe district. We measured total thyroxine (T4) and thyroid-stimulating hormone (TSH) in dried blood spots collected via heel stick. We found that all pyrethroid metabolites were positively associated with TSH; trans-DCCA and 3-PBA showed the strongest associations with a 12.3% (95%CI = 3.0, 22.3) and 14.0% (95%CI = 0.5, 30.2) change for each 10-fold increase in biomarker concentration, respectively. These associations were substantially stronger among children from households below the South African food poverty line. DDT and DDE were associated with lower total T4 among boys only (β = −0.27 μg/dL per 10-fold increase; 95%CI = −0.47, −0.04). Results suggest that prenatal exposure to DDT, DDE and pyrethroid insecticides is associated with changes in neonatal thyroid hormones consistent with hypothyroidism/hypothyroxinemia and that sex and poverty modify associations. Further research is needed to confirm these findings and examine whether they have implications for child development.
•Indoor Residual Spraying (IRS) is used by 84 countries to control malaria.•There are limited data on the potential adverse health effects of IRS insecticides.•Maternal serum DDT and DDE concentrations were associated with lower T4 in male neonates but not in females.•Maternal urinary pyrethroid metabolites were related to higher TSH in neonates.•Associations with TSH were stronger among neonates from poor households.
Display omitted
Exposure to organophosphate esters (OPEs) is extensive, yet few studies have investigated their association with hormone levels or semen quality. Here, we studied the association ...between urinary concentrations of OPEs and their metabolites with hormone levels and semen parameters in men (n = 117) predominantly in the 20–29 years age range who were recruited from the greater Montreal area between 2009 and 2012. Urine, serum, and semen samples were analyzed for OPEs, hormones, and semen quality, respectively. Bis(2-ethylhexyl) phosphate (BEHP), bis(2,4-di-tert-butylphenyl) hydrogen phosphate (B2,4DtBPP), tris(2-chloroisopropyl) phosphate (TCIPP), diphenyl phosphate (DPHP), bis (2-butoxyethyl) phosphate (BBOEP) and di-cresyl phosphate (DCPs) were detected in urine at a frequency ≥ 95%. The highest geometric mean concentration was observed for DPHP (18.54 ng/mL) and the second highest was B2,4DtBPP (6.23 ng/mL). Associations between a doubling in analyte concentrations in urine and hormone levels and semen quality parameters were estimated using multivariable linear regression. B2,4DtBPP levels were positively associated with total T3 (β = 0.09; 95% CI: 0.01, 0.17). DPHP was inversely associated with estradiol (β = -2.56; 95% CI: −5.00, −0.17), and TCIPP was inversely associated with testosterone (β = -0.78; 95% CI: −1.40, −0.17). Concentrations of BCIPP were inversely associated with sperm concentrations (β = -7.76; 95% CI: −14.40, −0.61), progressive motility (β = − 4.98; 95% CI: −8.71, −1.09), and the sperm motility index (β = -9.72; 95% CI: −17.71, −0.96). In contrast, urinary DPHP concentrations were positively associated with the sperm motility (β = 4.37; 95% CI: 0.76, 8.12) and fertility indices (β = 6.64; 95% CI: 1.96, 11.53). Thus, OPE detection rates were high and exposure to several OPEs was associated with altered hormone levels and semen parameters. The possibility that OPEs affect male reproduction warrants further investigation.
PDF
