Neighborhood environmental factors linked to hospitalizations of older people for viral lower respiratory tract infections in Spain: a case-crossover study

Seasonal extreme temperatures and short-term fine particulate matter increases pediatric respiratory healthcare encounters in a sparsely populated region of the intermountain western United States

BACKGROUND

Western Montana, USA, experiences complex air pollution patterns with predominant exposure sources from summer wildfire smoke and winter wood smoke. In addition, climate change related temperatures events are becoming more extreme and expected to contribute to increases in hospital admissions for a range of health outcomes. Evaluating while accounting for these exposures (air pollution and temperature) that often occur simultaneously and may act synergistically on health is becoming more important.

METHODS

We explored short-term exposure to air pollution on children's respiratory health outcomes and how extreme temperature or seasonal period modify the risk of air pollution-associated healthcare events. The main outcome measure included individual-based address located respiratory-related healthcare visits for three categories: asthma, lower respiratory tract infections (LRTI), and upper respiratory tract infections (URTI) across western Montana for ages 0-17 from 2017-2020. We used a time-stratified, case-crossover analysis with distributed lag models to identify sensitive exposure windows of fine particulate matter (PM2.5) lagged from 0 (same-day) to 14 prior-days modified by temperature or season.

RESULTS

For asthma, increases of 1 µg/m3 in PM2.5 exposure 7-13 days prior a healthcare visit date was associated with increased odds that were magnified during median to colder temperatures and winter periods. For LRTIs, 1 µg/m3 increases during 12 days of cumulative PM2.5 with peak exposure periods between 6-12 days before healthcare visit date was associated with elevated LRTI events, also heightened in median to colder temperatures but no seasonal effect was observed. For URTIs, 1 unit increases during 13 days of cumulative PM2.5 with peak exposure periods between 4-10 days prior event date was associated with greater risk for URTIs visits that were intensified during median to hotter temperatures and spring to summer periods.

CONCLUSIONS

Delayed, short-term exposure increases of PM2.5 were associated with elevated odds of all three pediatric respiratory healthcare visit categories in a sparsely population area of the inter-Rocky Mountains, USA. PM2.5 in colder temperatures tended to increase instances of asthma and LRTIs, while PM2.5 during hotter periods increased URTIs.

Global burden study of lower respiratory infections linked to low temperatures: an analysis from 1990 to 2019

Low temperature conditions have been linked to a heightened susceptibility to lower respiratory infections (LRIs). Yet, our comprehension of the LRIs' disease burden due to such conditions remains limited, especially when considering the diverse socio-demographic indexes (SDIs) and climate types across various nations and regions. We examined the variations over time and space in the impact of LRIs due to low temperatures across a diverse set of 204 nations and regions, each with unique SDIs and climate types, spanning the years 1990 to 2019. Data from the Global Burden of Disease Study 2019 was used for this retrospective analysis. The burden of LRIs attributable to low temperatures was estimated by stratifying by sex, age, country, climate type, and SDI, including age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life year rate (ASDR). We employed Joinpoint models to compute the annual average percent changes (AAPCs) in order to evaluate the trends in LRIs burden due to low temperatures from 1990 to 2019. Furthermore, we utilized Poisson age-period-cohort models to forecast the global and income-specific trends in LRIs burden due to low temperatures for the period 2020-2044. Generalized additive mixed models were used to fit changes in the disease burden of different climate regions. The relationship between SDI and both ASMR and ASDR was determined using models grounded in Gaussian process regression. In general, since the year 1990, there has been a significant reduction in the worldwide impact of LRIs due to low temperatures. This decrease is particularly noticeable among infants and the elderly, as well as in regions with a boreal climate and those with an average SDI. In 2019, LRIs induced by low temperatures showed an ASMR of 2.2 (95% CI: 1.34, 3.07) and an ASDR of 53.73 (95% CI: 17.5, 93.22) for every 100,000 individuals. A global reduction was observed in the ASMR and ASDR for LRIs over the period from 1990 to 2019, showing a decrease of 60.27% and 77.5%, in that order. For ASMR and ASDR, the AAPC values were found to be - 3.3 (95% CI: - 3.4, - 3.1) and - 5 (95% CI: - 5.2, - 4.9), in that order. However, a contrasting pattern was observed in southern Latin America, where an increase was noted in the ASMR for LRIs induced by low temperatures [AAPC: 0.5; 95% CI: (0.3, 0.8)]. Low temperature has decreased as an environmental risk factor for LRIs globally over 30 years, especially in middle SDI regions and boreal climates, but remains important for infants and the elderly population.

Comparison of the association between different ozone indicators and daily respiratory hospitalization in Guangzhou, China

Background

Epidemiological studies have widely proven the impact of ozone (O₃) on respiratory mortality, while only a few studies compared the association between different O₃ indicators and health.

Methods

This study explores the relationship between daily respiratory hospitalization and multiple ozone indicators in Guangzhou, China, from 2014 to 2018. It uses a time-stratified case-crossover design. Sensitivities of different age and gender groups were analyzed for the whole year, the warm and the cold periods. We compared the results from the single-day lag model and the moving average lag model.

Results

The results showed that the maximum daily 8 h average ozone concentration (MDA8 O₃) had a significant effect on the daily respiratory hospitalization. This effect was stronger than for the maximum daily 1 h average ozone concentration (MDA1 O₃). The results further showed that O₃ was positively associated with daily respiratory hospitalization in the warm season, while there was a significantly negative association in the cold season. Specifically, in the warm season, O₃ has the most significant effect at lag 4 day, with the odds ratio (OR) equal to 1.0096 [95% confidence intervals (CI): 1.0032, 1.0161]. Moreover, at the lag 5 day, the effect of O₃ on the 15-60 age group was less than that on people older than 60 years, with the OR value of 1.0135 (95% CI: 1.0041, 1.0231) for the 60+ age group; women were more sensitive than men to O₃ exposure, with an OR value equal to 1.0094 (95% CI: 0.9992, 1.0196) for the female group.

Conclusion

These results show that different O₃ indicators measure different impacts on respiratory hospitalization admission. Their comparative analysis provided a more comprehensive insight into exploring associations between O₃ exposure and respiratory health.