Long-term exposure to ambient air pollution and asthma symptom score in the CONSTANCES cohort.

BACKGROUND: The asthma symptom score allows to consider asthma as a continuum and to investigate its risk factors. One previous study has investigated the association between asthma score and air pollution and only for nitrogen dioxide (NO2). We aimed to study the associations between particulate matter with an aerodynamic diameter lower than 2.5 µm (PM2.5), black carbon (BC) and NO2 and the asthma symptom score in adults from CONSTANCES, a French population-based cohort. METHODS: Asthma symptom score (range: 0-5) was based on the number of five self-reported symptoms of asthma in the last 12 months. Annual individual exposure to PM2.5, BC and NO2 was estimated at participants' residential address using hybrid land-use regression models. Cross-sectional associations of each pollutant with asthma symptom score were estimated using negative binomial regressions adjusted for age, sex, smoking status and socioeconomic position. Associations with each symptom were estimated using logistic regression. The effect of BC independent of total PM2.5 was investigated with a residual model. RESULTS: Analyses were conducted on 135 165 participants (mean age: 47.2 years, 53.3% women, 19.0% smokers, 13.5% ever asthma). The ratio of mean score was 1.12 (95% CI 1.10 to 1.14), 1.14 (95% CI 1.12 to 1.16) and 1.12 (95% CI 1.10 to 1.14) per one IQR increase of PM2.5 (4.86 µg/m3), BC (0.88 10-5 m-1) and NO2 (17.3 µg/m3). Positive and significant associations were also found for each asthma symptom separately. BC effect persisted independently of total PM2.5. CONCLUSION: Exposure to each pollutant was associated with increased asthma symptom score in adults. This study highlights that BC could be one of the most harmful particulate matter components.

Toward setting public health guidelines for chemicals in indoor settled dust?

Indoor settled dust may result in substantial human exposure to chemicals, especially by ingestion following hand-to-mouth or hand-to-object-to-mouth contact. As with other environmental media related to exposure, dust may thus be subject to regulation. An international scientific workshop was convened in Paris in September 2019 firstly to assess the relevance for public health of setting guidelines for indoor settled dust, and secondly to discuss scientific and technical challenges related to such guidelines. The main discussions and conclusions, with consensus achieved, are reported herein. Discussions concerned general considerations, objectives and definitions, relevance for a health-based guideline, units of measure, and finally derivation of the guideline. These points should be addressed when considering an indoor settled dust guideline as part of a policy to reduce exposure indoors to a given chemical or group of chemicals.

Outdoor Mold and Respiratory Health: State of Science of Epidemiological Studies.

BACKGROUND: Fungal spores are the predominant biological particulates in outdoor air. However, in contrast to pollens or outdoor air pollution, little is known about their respiratory health risks. OBJECTIVES: The objectives were to conduct the first review of epidemiological studies on the short- and long-term effects of outdoor mold exposure on respiratory health in children and adults. METHODS: Health outcomes included asthma, lung function, and rhinitis. Cross-sectional and longitudinal epidemiological studies using quantitative measures of outdoor mold exposure (optical microscopy, culture-based methods) were selected, providing that important confounding factors including temporal trends or meteorological factors were accounted for. A systematic literature search was performed up to June 2020, leading to the selection of 37 publications. RESULTS: Most studies were longitudinal and investigated short-term effects. There is evidence of an association between outdoor fungal exposure and an increase in asthma exacerbation among children for total spores, 2 phyla (ascomycetes, basidiomycetes), and 2 taxa (Cladosporium, Alternaria). A few studies also suggested an association for Coprinus, Ganoderma, Aspergillus-Penicillium, Botrytis, and Epicoccum in children, but this needs to be confirmed. Some studies reported mold associations with rhinitis, lung function, and among adults, but these were few in number or inconsistent. DISCUSSION: Further ecological studies in different regions that measure exposure to all taxa over several years are required to better understand their impact on rhinitis, asthma exacerbations and lung function. Larger panel studies are necessary to identify threshold effects in susceptible individuals. Finally, further research should assess the long-term effects of outdoor mold.

Indoor mould exposure, asthma and rhinitis: findings from systematic reviews and recent longitudinal studies.

Starting from the Institute of Medicine (IOM) and World Health Organization (WHO) reports, this review provides an overview of the literature published from 2006 to 2017 on the associations between indoor mould exposure and asthma and rhinitis separately in children and adults with a focus on longitudinal epidemiological studies.A systematic search of peer-reviewed literature was performed, including systematic reviews and meta-analyses, longitudinal, incident case-control and panel studies. 61 publications were identified reporting visible mould or mould odour or quantitative assessment of culturable fungi or mould species.In children, visible mould and mould odour were associated with the development and exacerbations of asthma, providing sufficient evidence of a causal relationship. Results from population-based studies in adults were too few and divergent to conclude at more than a limited level of evidence. Exposure to mould in a work building was associated with the incidence and exacerbations of occupational asthma, and we concluded at a sufficient evidence for an association. Systematic reviews, meta-analyses and longitudinal studies on the relationships between mould exposure and allergic rhinitis provide sufficient evidence of an association.This review extended the conclusions of the IOM and WHO reports, and highlighted the need for further longitudinal studies on asthma in adults, and on rhinitis.