Nearly 3 billion people worldwide rely on solid fuel combustion to meet basic household energy needs. The resulting exposure to air pollution causes an estimated 4.5% of the global burden of disease. ...Large variability and a lack of resources for research and development have resulted in highly uncertain exposure estimates.
We sought to identify research priorities for exposure assessment that will more accurately and precisely define exposure-response relationships of household air pollution necessary to inform future cleaner-burning cookstove dissemination programs.
As part of an international workshop in May 2011, an expert group characterized the state of the science and developed recommendations for exposure assessment of household air pollution.
The following priority research areas were identified to explain variability and reduce uncertainty of household air pollution exposure measurements: improved characterization of spatial and temporal variability for studies examining both short- and long-term health effects; development and validation of measurement technology and approaches to conduct complex exposure assessments in resource-limited settings with a large range of pollutant concentrations; and development and validation of biomarkers for estimating dose. Addressing these priority research areas, which will inherently require an increased allocation of resources for cookstove research, will lead to better characterization of exposure-response relationships.
Although the type and extent of exposure assessment will necessarily depend on the goal and design of the cookstove study, without improved understanding of exposure-response relationships, the level of air pollution reduction necessary to meet the health targets of cookstove interventions will remain uncertain.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, OILJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity.
A ...search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO).
Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value.
There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries.
A third of the world's population uses solid fuel derived from plant material (biomass) or coal for cooking, heating, or lighting. These fuels are smoky, often used in an open fire or simple stove ...with incomplete combustion, and result in a large amount of household air pollution when smoke is poorly vented. Air pollution is the biggest environmental cause of death worldwide, with household air pollution accounting for about 3·5-4 million deaths every year. Women and children living in severe poverty have the greatest exposures to household air pollution. In this Commission, we review evidence for the association between household air pollution and respiratory infections, respiratory tract cancers, and chronic lung diseases. Respiratory infections (comprising both upper and lower respiratory tract infections with viruses, bacteria, and mycobacteria) have all been associated with exposure to household air pollution. Respiratory tract cancers, including both nasopharyngeal cancer and lung cancer, are strongly associated with pollution from coal burning and further data are needed about other solid fuels. Chronic lung diseases, including chronic obstructive pulmonary disease and bronchiectasis in women, are associated with solid fuel use for cooking, and the damaging effects of exposure to household air pollution in early life on lung development are yet to be fully described. We also review appropriate ways to measure exposure to household air pollution, as well as study design issues and potential effective interventions to prevent these disease burdens. Measurement of household air pollution needs individual, rather than fixed in place, monitoring because exposure varies by age, gender, location, and household role. Women and children are particularly susceptible to the toxic effects of pollution and are exposed to the highest concentrations. Interventions should target these high-risk groups and be of sufficient quality to make the air clean. To make clean energy available to all people is the long-term goal, with an intermediate solution being to make available energy that is clean enough to have a health impact.
Depression is a common and significant health problem. Hearing loss is the third most common chronic physical condition in the USA and might be a factor in depression. To determine whether hearing ...loss is associated with depressive symptoms in US adults ages 20-69 years.
National Health and Nutrition Examination Survey (NHANES) data (2011-2012) were used to assess the potential relationship between hearing loss and depression, in adults (20-69 years) who answered the Patient Health Questionnaire (PHQ-9) depression screening module, with pure tone audiometry measurements, and complete information on the co-variates data (n = 3316). The degree of speech-frequency hearing loss (SFHL) and high-frequency hearing loss (HFHL) were defined as slight/mild hearing loss ⩾26-40 dB; moderate/worse hearing loss ⩾41 dB by pure tone audiometry examination.
Moderate/worse HFHL was statistically significantly associated with depressive symptoms (OR 1.54, 95% CL 1.04-2.27) when the analyses were conducted among all participants. Further stratification by gender and age groups found that moderate/worse HFHL (OR 3.85, 95% CL 1.39-10.65) and moderate/worse SFHL (OR 5.75, 95% CL 1.46-22.71) were associated with depressive symptoms in women ages 52-69 years.
Moderate/worse speech frequency and HFHL are associated with depression in women ages 52-69 years, independent of other risk factors. Hearing screenings are likely to reduce delays in diagnosis and provide early opportunities for noise prevention counseling and access to hearing aids. Health professionals should be aware of depressive signs and symptoms in patients with hearing loss.
Introduction Chemical contamination and pollution are an ongoing threat to human health and the environment. The concern over the consequences of chemical exposures at the global level continues to ...grow. Because resources are constrained, there is a need to prioritize interventions focused on the greatest health impact. Data, especially related to chemical exposures, are rarely available for most substances of concern, and alternate methods to evaluate their impact are needed. Structured expert judgment (SEJ) process A Structured Expert Judgment (Research Outreach, 2021) process was performed to provide plausible estimates of health impacts for 16 commonly found pollutants: asbestos, arsenic, benzene, chromium, cadmium, dioxins, fluoride, highly hazardous pesticides (HHPs), lead, mercury, polycyclic-aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), Per- and Polyfluorinated Substances (PFAs), phthalates, endocrine disrupting chemicals (EDCs), and brominated flame retardants (BRFs). This process, undertaken by sector experts, weighed individual estimations of the probable global health scale health impacts of each pollutant using objective estimates of the expert opinions’ statistical accuracy and informativeness. Main findings The foremost substances, in terms of mean projected annual total deaths, were lead, asbestos, arsenic, and HHPs. Lead surpasses the others by a large margin, with an estimated median value of 1.7 million deaths annually. The three other substances averaged between 136,000 and 274,000 deaths per year. Of the 12 other chemicals evaluated, none reached an estimated annual death count exceeding 100,000. These findings underscore the importance of prioritizing available resources on reducing and remediating the impacts of these key pollutants. Range of health impacts Based on the evidence available, experts concluded some of the more notorious chemical pollutants, such as PCBs and dioxin, do not result in high levels of human health impact from a global scale perspective. However, the chemical toxicity of some compounds released in recent decades, such as Endocrine Disrupters and PFAs, cannot be ignored, even if current impacts are limited. Moreover, the impact of some chemicals may be disproportionately large in some geographic areas. Continued research and monitoring are essential; and a preventative approach is needed for chemicals. Future directions These results, and potential similar analyses of other chemicals, are provided as inputs to ongoing discussions about priority setting for global chemicals and pollution management. Furthermore, we suggest that this SEJ process be repeated periodically as new information becomes available.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Indoor particulate matter is associated with worse chronic obstructive pulmonary disease (COPD) outcomes. It remains unknown whether reductions of indoor pollutants improve respiratory morbidity.
To ...determine whether placement of active portable high-efficiency particulate air cleaners can improve respiratory morbidity in former smokers.
Eligible former smokers with moderate-to-severe COPD received active or sham portable high-efficiency particulate absolute air cleaners and were followed for 6 months in this blinded randomized controlled trial. The primary outcome was 6-month change in St. George's Respiratory Questionnaire (SGRQ). Secondary outcomes were exacerbation risk, respiratory symptoms, rescue medication use, and 6-minute-walk distance (6MWD). Intention-to-treat analysis included all subjects, and per-protocol analysis included adherent participants (greater than 80% use of air cleaner).
A total of 116 participants were randomized, of which 84.5% completed the study. There was no statistically significant difference in total SGRQ score, but the active filter group had greater reduction in SGRQ symptom subscale (β, -7.7 95% confidence interval (CI), -15.0 to -0.37) and respiratory symptoms (Breathlessness, Cough, and Sputum Scale, β, -0.8 95% CI, -1.5 to -0.1); and lower rate of moderate exacerbations (incidence rate ratio, 0.32 95% CI, 0.12-0.91) and rescue medication use (incidence rate ratio, 0.54 95% CI, 0.33-0.86) compared with sham group (all
< 0.05). In per-protocol analysis, there was a statistically significant difference in primary outcome between the active filter versus sham group (SGRQ, β -4.76 95% CI, -9.2 to -0.34) and in moderate exacerbation risk, Breathlessness, Cough, and Sputum Scale, and 6MWD. Participants spending more time indoors were more likely to have treatment benefit.
This is the first environmental intervention study conducted among former smokers with COPD showing potential health benefits of portable high-efficiency particulate absolute air cleaners, particularly among those with greater adherence and spending a greater time indoors.
Air pollution exposure may contribute to rhinoconjunctivitis morbidity in children with underlying airways disease. Prior studies have not assessed rhinoconjunctivitis-related quality of life (QOL) ...in children with asthma chronically exposed to air pollution.
Children ages 9-19 years with asthma from peri-urban Peru, self-reporting rhinoconjunctivitis symptoms (n = 484), were administered the Rhinoconjunctivitis QOL Questionnaire (RQLQ) at repeated intervals over one year, with scores dichotomized into bothered (>0) and not bothered (= 0). Individual weekly exposures to particulate matter<2.5μm (PM2.5) and its black carbon (BC) component were estimated by inverse distance weighted methods. Generalized estimating equations, adjusting for covariates, estimated associations of PM2.5 and BC with QOL.
Participants were on average 13 years old, 55% female, and majority were atopic (77%). Mean (SD) PM2.5 and BC concentrations were 21(3.2) μg/m3 and 4.4(1.5) μg/m3, respectively. In adjusted multi-pollutant models, each 10μg/m3 increase in PM2.5 was associated with increased odds of worse rhinoconjunctivitis QOL (OR;95% CI: 1.83;1.33,2.52). A 10% increase in the BC proportion was associated with higher rhinitis burden (OR;95% CI: 1.80;1.22,2.66), while increases in the non-BC component of PM did not significantly impact rhinoconjunctivitis QOL. Associations were similar regardless of atopy.
Higher PM2.5 and BC exposure is associated with worse rhinitis QOL among asthmatic children.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Exposure to particulate matter (PM) is a significant risk factor for increased cardiopulmonary morbidity and mortality. The mechanism of PM-mediated pathophysiology remains unknown. However, PM is ...proinflammatory to the endothelium and increases vascular permeability in vitro and in vivo via ROS generation.
We explored the role of tight junction proteins as targets for PM-induced loss of lung endothelial cell (EC) barrier integrity and enhanced cardiopulmonary dysfunction.
Changes in human lung EC monolayer permeability were assessed by Transendothelial Electrical Resistance (TER) in response to PM challenge (collected from Ft. McHenry Tunnel, Baltimore, MD, particle size >0.1 μm). Biochemical assessment of ROS generation and Ca2+ mobilization were also measured.
PM exposure induced tight junction protein Zona occludens-1 (ZO-1) relocation from the cell periphery, which was accompanied by significant reductions in ZO-1 protein levels but not in adherens junction proteins (VE-cadherin and β-catenin). N-acetyl-cysteine (NAC, 5 mM) reduced PM-induced ROS generation in ECs, which further prevented TER decreases and atteneuated ZO-1 degradation. PM also mediated intracellular calcium mobilization via the transient receptor potential cation channel M2 (TRPM2), in a ROS-dependent manner with subsequent activation of the Ca2+-dependent protease calpain. PM-activated calpain is responsible for ZO-1 degradation and EC barrier disruption. Overexpression of ZO-1 attenuated PM-induced endothelial barrier disruption and vascular hyperpermeability in vivo and in vitro.
These results demonstrate that PM induces marked increases in vascular permeability via ROS-mediated calcium leakage via activated TRPM2, and via ZO-1 degradation by activated calpain. These findings support a novel mechanism for PM-induced lung damage and adverse cardiovascular outcomes.
Background Cockroach and mouse allergens have both been implicated as causes in inner-city asthma morbidity in multicenter studies, but whether both allergens are clinically relevant within specific ...inner-city communities is unclear. Objective Our study aimed to identify relevant allergens in Baltimore City. Methods One hundred forty-four children (5-17 years old) with asthma underwent skin prick tests at baseline and had clinical data collected at baseline and 3, 6, 9, and 12 months. Home settled dust samples were collected at the same time points for quantification of indoor allergens. Participants were grouped based on their sensitization and exposure status to each allergen. All analyses were adjusted for age, sex, and serum total IgE level. Results Forty-one percent were mouse sensitized/exposed, and 41% were cockroach sensitized/exposed based on bedroom floor exposure data. Mouse sensitization/exposure was associated with acute care visits, decreased FEV1 /forced vital capacity percentage values, fraction of exhaled nitric oxide levels, and bronchodilator reversibility. Cockroach sensitization/exposure was only associated with acute care visits and bronchodilator reversibility when exposure was defined by using bedroom floor allergen levels. Mouse-specific IgE levels were associated with poor asthma health across a range of outcomes, whereas cockroach-specific IgE levels were not. The relationships between asthma outcomes and mouse allergen were independent of cockroach allergen. Although sensitization/exposure to both mouse and cockroach was generally associated with worse asthma, mouse sensitization/exposure was the primary contributor to these relationships. Conclusions In a community with high levels of both mouse and cockroach allergens, mouse allergen appears to be more strongly and consistently associated with poor asthma outcomes than cockroach allergen. Community-level asthma interventions in Baltimore should prioritize reducing mouse allergen exposure.
Asthma development and pathogenesis are influenced by the interactions of airway epithelial cells and innate and adaptive immune cells in response to allergens. Oxidative stress is an important ...mediator of asthmatic phenotypes in these cell types. Nuclear erythroid 2-related factor 2 (Nrf2) is a redox-sensitive transcription factor that is the key regulator of the response to oxidative and environmental stress. We previously demonstrated that Nrf2-deficient mice have heightened susceptibility to asthma, including elevated oxidative stress, inflammation, mucus, and airway hyperresponsiveness (AHR) (Rangasamy T, Guo J, Mitzner WA, Roman J, Singh A, Fryer AD, Yamamoto M, Kensler TW, Tuder RM, Georas SN, Biswal S. J Exp Med 202: 47-59, 2005). Here we dissected the role of Nrf2 in lung epithelial cells and tested whether genetic or pharmacological activation of Nrf2 reduces allergic asthma in mice. Cell-specific activation of Nrf2 in club cells of the airway epithelium significantly reduced allergen-induced AHR, inflammation, mucus, Th2 cytokine secretion, oxidative stress, and airway leakiness and increased airway levels of tight junction proteins zonula occludens-1 and E-cadherin. In isolated airway epithelial cells, Nrf2 enhanced epithelial barrier function and increased localization of zonula occludens-1 to the cell surface. Pharmacological activation of Nrf2 by 2-trifluoromethyl-2'-methoxychalone during the allergen challenge was sufficient to reduce allergic inflammation and AHR. New therapeutic options are needed for asthma, and this study demonstrates that activation of Nrf2 in lung epithelial cells is a novel potential therapeutic target to reduce asthma susceptibility.
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