Associations of Preconception Exposure to Air Pollution and Greenness with Offspring Asthma and Hay Fever

Abstract

We investigated if greenness and air pollution exposure in parents’ childhood affect offspring asthma and hay fever, and if effects were mediated through parental asthma, pregnancy greenness/pollution exposure, and offspring exposure. We analysed 1106 parents with 1949 offspring (mean age 35 and 6) from the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study. Mean particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), black carbon (BC), ozone (O3) (µg/m3) and greenness (normalized difference vegetation index (NDVI)) were calculated for parents 0–18 years old and offspring 0–10 years old, and were categorised in tertiles. We performed logistic regression and mediation analyses for two-pollutant models (clustered by family and centre, stratified by parental lines, and adjusted for grandparental asthma and education). Maternal medium PM2.5 and PM10 exposure was associated with higher offspring asthma risk (odds ratio (OR) 2.23, 95%CI 1.32–3.78, OR 2.27, 95%CI 1.36–3.80), and paternal high BC exposure with lower asthma risk (OR 0.31, 95%CI 0.11–0.87). Hay fever risk increased for offspring of fathers with medium O3 exposure (OR 4.15, 95%CI 1.28–13.50) and mothers with high PM10 exposure (OR 2.66, 95%CI 1.19–5.91). The effect of maternal PM10 exposure on offspring asthma was direct, while for hay fever, it was mediated through exposures in pregnancy and offspring’s own exposures. Paternal O3 exposure had a direct effect on offspring hay fever. To conclude, parental exposure to air pollution appears to influence the risk of asthma and allergies in future offspring.

Maternal preconception occupational exposure to cleaning products and disinfectants and offspring asthma

“…Furthermore, a recent analysis found higher asthma risk in offspring if mothers had been exposed to air pollution before age 18 years. 20 A role of preconception occupational exposure through the paternal line was suggested in an analysis of fathers' exposure to welding and metal fumes, showing increased asthma related to preconception exposure but no effect of postnatal exposure. 18 Indirect support to a role of preconception occupational exposure in childhood asthma is provided by a Swedish registry study that found that several occupations, in which the employees most likely would have been exposed to cleaning agents, were associated with an increased risk of hospitalization for childhood asthma in offspring.…”

“…26 Emerging evidence from animal and human studies supports that environmental and occupational exposures might cause epigenetic changes that might be transmissible to offspring. [14][15][16][17][18][19][20][21][22]39 Such environmentally induced epigenetic alterations must be present in the germline to be transmissible to the next generation. 13,24 Alterations passed through the germline might result in inherited changes in gene expression in offspring in any kind of tissue and hence induce alteration in various tissues and cell types with impact on offspring phenotype.…”

“…13 Emerging evidence from human and animal models suggests that preconception parental exposures may influence the health of future generations. [14][15][16][17][18][19][20][21][22][23][24] Previous studies on maternal occupational exposure and respiratory health in offspring are scarce. [25][26][27] However, a registry study found that several parental occupations were associated with increased hospitalization for childhood asthma among offspring.…”

NeuroSmog: Determining the impact of air pollution on the developing brain: project protocol

“…The General Questionnaire is a Qualtrics-based tool filled in by a legal guardian that collects data on confounders, effect modifiers, and additional exposures. Some items were adopted from the existing studies (Dzhambov et al 2018a;Dzhambov et al 2018b;Heinrich et al 2017;Kuiper et al 2020), and some of the items were invented for the purpose of NeuroSmog. Briefly, information on socio-demographics, pregnancy and early life, general health, habits, academic performance, home, and neighbourhood environments of the child is being collected (see Supplement A for a paper-adopted version of the questionnaire).…”

Vegetation, Air Pollution, and Asthma and Allergy: A Narrative Review

“…The results of cellular and animal models' studies support the notion that particulate and gaseous air pollutants generate reactive oxygen species, which results in oxidative stress and inflammatory responses 8 . The results of one recent study demonstrate that parental early-life exposure to particulate air pollution and ozone even in relatively clean Norway and Sweden increased the risk of asthma and hay fever in future offspring, which points out towards transgenerational effects of air pollution on allergy 9 .…”