Use of biocidal products (insect sprays and electro-vaporizer) in indoor areas – Exposure scenarios and exposure modeling

Five commercially available insect sprays were applied in a model room. Spraying was performed in accordance with the manufacturers’ instructions and in an overdosed manner in order to simulate worst-case conditions or an unforeseeable misuse. In addition, we examined electro-vaporizers. The Respicon™ aerosol monitoring system was applied to determine inhalation exposure. During normal spraying (10 seconds) and during the following 2–3 minutes, exposure concentrations ranged from 70 to 590 μg/m³ for the pyrethroids tetramethrin, d-phenothrin, cyfluthrin, bioallethrin, and the pyrethrins. Calculated inhalable doses were 2–16 μg. A concentration of approximately 850 μg chlorpyrifos/m³ (inhalable dose: approximately 20 μg) was determined when the “Contra insect fly spray” was applied. Highest exposure concentrations (1100–2100 μg/m³) were measured for piperonyl butoxide (PBO), corresponding to an inhalation intake of 30–60 μg. When simulating worst-case conditions, exposure concentrations of 200–3400 μg/m³ and inhalable doses of 10–210 μg were determined for the various active substances. Highest concentrations (4800–8000 μg/m³) were measured for PBO (inhalable: 290–480 μg).By applying the electro-vaporizer “Nexa Lotte” plug-in mosquito killer concentrations for d-allethrin were in the range of 5–12 μg/m³ and 0.5–2 μg/m³ for PBO while with the “Paral” plug-in mosquito killer concentrations of 0.4–5 μg/m³ for pyrethrins and 1–7 μg/m³ for PBO were measured.Potential dermal exposures were determined using exposure pads. Between 80 and 1000 μg active substance (tetramethrin, phenothrin, cyfluthrin, bioallethrin, pyrethrins, chlorpyrifos) were deposited on the clothing of the total body surface area of the spray user. Highest levels (up to 3000 μg) were determined for PBO. Worst-case uses of the sprays led to 5–9 times higher concentrations.Also a 2-hour stay nearby an operating electro-vaporizer led to a contamination of the clothing (total amounts on the whole body were 450 μg d-allethrin and 50 μg PBO for “Nexa Lotte” plug-in mosquito killer and 80 μg pyrethrins and 190 μg PBO for “Paral” plug-in mosquito killer).Human biomonitoring data revealed urine concentrations of the metabolite (E)-trans-chrysanthemum dicarboxylic acid ((E)-trans-CDCA) between 1.7 μg/l and 7.1 μg/l after 5 minutes of exposure to the different sprays. Also the use of electro-vaporizers led to (E)-trans-CDCA concentrations in the urine in the range of 1.0 μg/l to 6.2 μg/l (1–3 hours exposure period).The exposure data presented can be used for performing human risk assessment when these biocidal products were applied indoors.The airborne concentrations of the non-volatile active chemical compounds could be predicted from first principles using a deterministic exposure model (SprayExpo).     

Quantifying behavioural interactions between humans and mosquitoes: Evaluating the protective efficacy of insecticidal nets against malaria transmission in rural Tanzania

Background  

African malaria vectors bite predominantly indoors at night so sleeping under an Insecticide-Treated Net (ITN) can greatly reduce malaria risk. Behavioural adaptation by mosquitoes to increasing ITN coverage could allow vector mosquitoes to bite outside of peak sleeping hours and undermine efficacy of this key malaria prevention measure.     

Cognitive appraisal biases: An approach to understanding the relation between socioeconomic status and cardiovascular reactivity in children

We tested the hypothesis that lower socioeconomic status (SES) children display heightened cardiovascular reactivity during stressful situations because they are more likely to appraise a wide variety of social situations, including ambiguous ones, as threatening. A sample of 201 children and adolescents, half White and half African American, were assessed initially. Ninety of these children were retested an average of 3 years later. At both time points, children were interviewed about appraisals of hostile intent and feelings of anger in response to scenarios with negative or ambiguous outcomes. Cardiovascular reactivity to 3 laboratory stress tasks was measured. Initially, lower SES was associated with greater hostile intent appraisal and anger during ambiguous scenarios across all participants. In addition, responses to ambiguous scenarios partially mediated the relation between SES and vascular reactivity. Longitudinally, low SES African American participants showed higher mean intensity of hostile intent appraisals during ambiguous scenarios, and these appraisals mediated the SES-reactivity relationship. These findings suggest that the way in which children appraise ambiguous social situations plays an important role in the relation between SES and cardiovascular reactivity. This research was supported by National Institute of Health Grants HL25767 and MH18269, the John D. and Catherine T. Mac Arthur Foundation Research Network on SES and Health, and the Pittsburgh Mind-Body Center (HL65111 and HL65112). We thank Linda Gallo and Gregory Miller for helpful comments on earlier versions of this article.     

Cost-Effectiveness of a Diabetes Self-Management Education and Support Intervention Led by Community Health Workers and Peer Leaders: Projections From the Racial and Ethnic Approaches to Community Health Detroit Trial

OBJECTIVETo simulate the long-term cost-effectiveness of a peer leader (PL)–led diabetes self-management support (DSMS) program following a structured community health worker (CHW)–led diabetes self-management education (DSME) program in reducing risks of complications in people with type 2 diabetes (T2D).RESEARCH DESIGN AND METHODSThe trial randomized 222 Latino adults with T2D to 1) enhanced usual care (EUC); 2) a CHW-led, 6-month DSME program and 6 months of CHW-delivered monthly telephone outreach (CHW only); or 3) a CHW-led, 6-month DSME program and 12 months of PL-delivered weekly group sessions with telephone outreach to those unable to attend (CHW + PL). Empirical data from the trial and the validated Michigan Model for Diabetes were used to estimate cost and health outcomes over a 20-year time horizon from a health care sector perspective, discounting both costs and benefits at 3% annually. The primary outcome measure was the incremental cost-effectiveness ratio (ICER).RESULTSOver 20 years, the CHW + PL intervention had an ICER of $28,800 and $5,900 per quality-adjusted life-year (QALY) gained compared with the EUC and CHW-only interventions, respectively. The CHW-only intervention had an ICER of $430,600 per QALY gained compared with the EUC intervention. In sensitivity analyses, the results comparing the CHW + PL with EUC and CHW-only interventions were robust to changes in intervention effects and costs.CONCLUSIONSThe CHW + PL–led DSME/DSMS intervention improved health and provided good value compared with the EUC intervention. The 6-month CHW-led DSME intervention without further postintervention CHW support was not cost effective in Latino adults with T2D.     

The effects of persuasive messages on cancer patients’ attitudes,norms and intention to express concerns

Objective

To examine whether the use of persuasive messages in which cancer patients’ attitudes and perceived social norms were either simultaneously or exclusively targeted can positively change patients’ attitudes, perceived social norms and the intention to express concerns in consultations.

Generation of renal Epo-producing cell lines by conditional gene tagging reveals rapid HIF-2 driven Epo kinetics,cell autonomous feedback regulation,and a telocyte phenotype

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