The joint effect of cumulative doses for outdoor air pollutants exposure in early life on asthma and wheezing among young children

Background: Constrained by no proper way to assess cumulative exposure, the joint effect of air pollution cumulative exposure doses on childhood asthma and wheezing (AW) was not understood. Objective: To assess the association between cumulative exposure to multiple air pollutants in early life and childhood AW. Methods: We designed a nested case-control study based on the birth cohort in Jinan City. Children with AW followed up within 2 years after birth were treated as cases, and non-cases in this cohort were treated as the control source population, and the propensity score matching method was used to match each case to 5 controls. We calculated the individual cumulative outdoor exposure doses for each period using an inverse distance weighted model, alongside the complex Simpson's formula, accounting for outdoor time and respiratory volume. The Least absolute shrinkage and selection operator (Lasso) regression was performed to screen for covariates. To analyze the joint effects of pollutants, we employed the weighted quantile sum (WQS) regression model in conjunction with conditional logistic regression. Results: 84 cases and 420 controls were included in this study. The odds ratio (OR) with 95% confidence interval (CI) of the impact of cumulative exposure (mg/m3) after birth on childhood AW was 1.78 (1.15–2.74) for SO2, 1.69 (1.11–2.57) for NO2, and 1.65 (1.09–2.52) for PM2.5, respectively. Furthermore, with each 25th percentile increase in the WQS index, the overall risk of cumulative doses for six pollutants exposure after birth on AW increased by an adjusted OR of 1.10 (1.03, 1.18), and SO2, PM2.5, and NO2 contributed the most to the WQS index. However, no statistically significant association was found between cumulative exposure to all pollutants before birth and childhood AW. Conclusions: There was a joint effect of the cumulative exposure dose of outdoor air pollutants after birth on AW in children aged 0–2 years. And traffic-related pollutants (SO2, PM2.5, and NO2) make a greater contribution to the joint effect

The Characteristics of Air Pollutants during Two Distinct Episodes of Fireworks Burning in a Valley City of North China

<div><p>Background</p><p>The elevation and dissipation of pollutants after the ignition of fireworks in different functional areas of a valley city were investigated.</p><p>Methods</p><p>The Air Quality Index (AQI) as well as inter-day and intra-day concentrations of various air pollutants (PM₁₀, PM_2.5, SO₂, NO₂, CO, O₃) were measured during two episodes that took place during Chinese New Year festivities.</p><p>Results</p><p>For the special terrain of Jinan, the mean concentrations of pollutants increased sharply within 2–4 h of the firework displays, and concentrations were 4–6 times higher than the usual levels. It took 2–3 d for the pollutants to dissipate to background levels. Compared to Preliminary Eve (more fireworks are ignited on New Year’s Eve, but the amounts of other human activities are also lesser), the primary pollutants PM_2.5, PM₁₀, and CO reached higher concentrations on New Year’s Eve, and the highest concentrations of these pollutants were detected in living quarters. All areas suffered from serious pollution problems on New Year’s Eve (rural = urban for PM₁₀, but rural > urban for PM_2.5). However, SO₂ and NO₂ levels were 20%–60% lower in living quarters and industrial areas compared to the levels in these same areas on Preliminary Eve. In contrast to the other pollutants, O₃ concentrations fell instead of rising with the firework displays.</p><p>Conclusion</p><p>Interactions between firework displays and other human activities caused different change trends of pollutants. PM_2.5 and PM₁₀ were the main pollutants, and the rural living quarter had some of the highest pollution levels.</p></div

Inter-day changes of the pollutant concentrations during the two episodes for the Chinese New Year.

<p>The unit of CO is 10⁻¹ mg m^-3 and others are mg m^-3.</p

The Air Quality Index (AQI) and main pollutants in different sites before and after firework burning on Preliminary Eve.

<p>The Air Quality Index (AQI) and main pollutants in different sites before and after firework burning on Preliminary Eve.</p

Distribution of monitoring sites in Jinan, where A1, A2, A3 are living quarters in urban areas; A4 is a living quarter in the suburbs; B1, B2 are the industrial zones in the suburbs; C1 is a tourist area in the countryside and C2 is a living quarter in the countryside; D1 is a mixed area containing living quarter and an industrial zone.

<p>Values in brackets are the elevations.</p

The Air Quality Index (AQI) and the main pollutants during three phases of firework burning on New Year’s Eve.

<p>The Air Quality Index (AQI) and the main pollutants during three phases of firework burning on New Year’s Eve.</p