Prenatal and early-life exposure to traffic-related air pollution and allergic rhinitis in children: A systematic literature review

BACKGROUND: Traffic-related air pollution (TRAP) is hypothesised to play a role in the development of allergic rhinitis (AR). Prenatal and early-life exposure to traffic-related air pollution is considered critical for later respiratory health. However, we could not find any articles systematically reviewing the risk of prenatal and early-life exposure to traffic-related air pollution for allergic rhinitis in children. METHODS: A systematic literature search of PubMed, Web of Science and Medline was conducted to identify studies focused on the association between prenatal and early-life exposure to TRAP and AR in children. Other inclusion criteria were: 1) original articles; 2) based upon prospective or retrospective studies or case-control studies; and 3) publications were restricted to English. Literature quality assessment was processed using the Newcastle-Ottawa Scale (NOS) evaluation scale. This systematic literature review has been registered on the prospero (crd.york.ac.uk/prospero) with the following registry number: CRD42022361179. RESULTS: Only eight studies met the inclusion criteria. The exposure assessment indicators included PM(2.5), PM(2.5) absorbance, PM(10), NO(x), CO, and black carbon. On the whole, exposure to TRAP during pregnancy and the first year of life were positively associated with the development of AR in children. CONCLUSIONS: This systematic review presents supportive evidence about prenatal and early-life exposure to TRAP and the risk of AR in children.