Exposure to DDT from indoor residual spraying and biomarkers of inflammation among reproductive-aged women from South Africa

BACKGROUND : Evidence from animal studies suggests that DDT and DDE can adversely affect immuno-competence while human data are less conclusive. We aimed to assess the association of plasma concentrations of DDT and DDE with biomarkers of inflammation among reproductive-aged women residing in homes sprayed with DDT through Indoor Residual Spraying (IRS). METHODS : This study included 416 women from the Study of Women and Babies, South Africa (2010–2011). DDT, DDE, and biomarkers of inflammation (immunoglobulins A, G and M, interleukins 1β, 6, and 8, tumor necrosis factor-α, C-reactive protein, serum amyloid-A, intercellular adhesion molecule-1, vascular cell adhesion molecule-1) were quantified in plasma. Linear regression was used to assess associations of DDT and DDE with each natural log-transformed biomarker. Models were adjusted for age, body mass index, parity, income, and season; beta estimates were expressed as percent differences. RESULTS : Compared to women with the lowest plasma concentrations of DDT and DDE, those with the highest concentrations of both compounds had higher levels IL-1β, IL6, and TNF- α. While associations were statistically significant for both DDT and DDE, the magnitude of the associations was slightly stronger for DDT. Compared to women in the lowest quintile of DDT, women in the highest quintile were estimated to have 53.0% (95%CI: 21.7%, 84.4%), 28.1% (95%CI: 6.4%, 49.8%), and 26.6% (95%CI: 12.0%, 41.1%) higher levels of IL-1β, IL6, and TNF- α, respectively. CONCLUSIONS : Our results suggest that increased plasma concentrations of DDT and DDE resulting from exposure to IRS may increase concentrations of pro-inflammatory biomarkers among reproductive-aged women in South Africa.The National Institute of Environmental Health Sciences, National Institutes of Health; and the Intramural Research Program of the NIH, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.http://www.elsevier.com/locate/envres2021-12-01hj2020School of Health Systems and Public Health (SHSPH

Target company cross-border effects in acquisitions into the UK

We analyse the abnormal returns to target shareholders in crossborder and domestic acquisitions of UK companies. The crossborder effect during the bid month is small (0.84%), although crossborder targets gain significantly more than domestic targets during the months surrounding the bid. We find no evidence for the level of abnormal returns in crossborder acquisitions to be associated with market access or exchange rate effects, and only limited support for an international diversification effect. However, the crossborder effect appears to be associated with significant payment effects, and there is no significant residual crossborder effect once various bid characteristics are controlled for

Predictors of plasma DDT and DDE concentrations among women exposed to indoor residual spraying for malaria control in the South African Study of Women and Babies (SOWB)

BACKGROUND : Few studies have examined predictors of DDT (dichlorodiphenyltrichloroethane) and DDE (dichlorodiphenyldichloroethylene) levels among residents in homes sprayed with DDT for malaria control with the aim of identifying exposure-reduction strategies. METHODS : The present analysis included 381 women enrolled in the Study of Women and Babies (SOWB) during 2010–2011, from eight South African villages in the Limpopo Province, South Africa. Indoor residual spraying (IRS) occurred in half of the villages. Questionnaires regarding various demographic and medical factors were administered and blood samples were obtained. We classified the women into three exposure groups by type of residence: unsprayed village (n = 175), IRS village in household with a low likelihood of DDT use (non-DDT IRS household, n = 106), IRS village in household with a high likelihood of DDT use (DDT IRS household, n = 100). We used multivariable models of natural log-transformed DDT plasma levels (in micrograms per liter) and DDE (in micrograms per liter) to identify predictors for each group. RESULTS : Median levels of DDT and DDE among women in unsprayed villages were 0.3 [interquartile range (IQR): 0.1–0.9] and 1.7 (IQR: 0.7–5.5), respectively. Median levels of DDT and DDE among women in DDT IRS households were 2.6 (IQR: 1.1–6.6) and 8.5 (IQR: 4.7–18.0), respectively. In unsprayed villages, women with water piped to the yard, rather than a public tap, had 73% lower DDT (95% CI: –83, –57%) and 61% lower DDE (95% CI: –74, –40%) levels. In DDT IRS households, women who reported taking more than six actions to prepare their home before IRS (e.g., covering water and food) had 40% lower DDT levels (95% CI: –63, –0.3%) than women who took fewer than four actions. CONCLUSION : The predictors of DDT and DDE plasma levels identified in the present study may inform interventions aimed at decreasing exposure. Among households where DDT is likely to be used for IRS, education regarding home preparations may provide an interventional target.http://ehp.niehs.nih.gov/hb201

Perfluoroalkyl Substances During Pregnancy and Validated Preeclampsia Among Nulliparous Women in the Norwegian Mother and Child Cohort Study

Perfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants, and human exposure to these substances may be related to preeclampsia, a common pregnancy complication. Previous studies have found serum concentrations of PFAS to be positively associated with pregnancy-induced hypertension and preeclampsia in a population with high levels of exposure to perfluorooctanoate. Whether this association exists among pregnant women with background levels of PFAS exposure is unknown. Using data from the Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health, we carried out a study of nulliparous pregnant women enrolled in 2003–2007 (466 cases, 510 noncases) to estimate associations between PFAS concentrations and an independently validated diagnosis of preeclampsia. We measured levels of 9 PFAS in maternal plasma extracted midpregnancy; statistical analyses were restricted to 7 PFAS that were quantifiable in more than 50% of samples. In proportional hazards models adjusted for maternal age, prepregnancy body mass index (weight (kg)/height (m)2), educational level, and smoking status, we observed no strongly positive associations between PFAS levels and preeclampsia. We found an inverse association between preeclampsia and the highest quartile of perfluoroundecanoic acid concentration relative to the lowest quartile (hazard ratio = 0.55, 95% confidence interval: 0.38, 0.81). Overall, our findings do not support an increased risk of preeclampsia among nulliparous Norwegian women with background levels of PFAS exposure

Ontogeny-Driven rDNA Rearrangement, Methylation, and Transcription, and Paternal Influence

Gene rearrangement occurs during development in some cell types and this genome dynamics is modulated by intrinsic and extrinsic factors, including growth stimulants and nutrients. This raises a possibility that such structural change in the genome and its subsequent epigenetic modifications may also take place during mammalian ontogeny, a process undergoing finely orchestrated cell division and differentiation. We tested this hypothesis by comparing single nucleotide polymorphism-defined haplotype frequencies and DNA methylation of the rDNA multicopy gene between two mouse ontogenic stages and among three adult tissues of individual mice. Possible influences to the genetic and epigenetic dynamics by paternal exposures were also examined for Cr(III) and acid saline extrinsic factors. Variables derived from litters, individuals, and duplicate assays in large mouse populations were examined using linear mixed-effects model. We report here that active rDNA rearrangement, represented by changes of haplotype frequencies, arises during ontogenic progression from day 8 embryos to 6-week adult mice as well as in different tissue lineages and is modifiable by paternal exposures. The rDNA methylation levels were also altered in concordance with this ontogenic progression and were associated with rDNA haplotypes. Sperm showed highest level of methylation, followed by lungs and livers, and preferentially selected haplotypes that are positively associated with methylation. Livers, maintaining lower levels of rDNA methylation compared with lungs, expressed more rRNA transcript. In vitro transcription demonstrated haplotype-dependent rRNA expression. Thus, the genome is also dynamic during mammalian ontogeny and its rearrangement may trigger epigenetic changes and subsequent transcriptional controls, that are further influenced by paternal exposures