UNASSIGNED: Previous work reported increased rates of cardiovascular hospitalizations associated with increased source-specific PM2.5 concentrations in New York State, despite decreased PM2.5 concentrations. We also found increased rates of ST elevation myocardial infarction (STEMI) associated with short-term increases in concentrations of ultrafine particles and other traffic-related pollutants in the 2014-2016 period, but not during 2017-2019 in Rochester. Changes in PM2.5 composition and sources resulting from air quality policies (e.g., Tier 3 light-duty vehicles) may explain the differences. Thus, this study aimed to estimate whether rates of STEMI were associated with organic carbon and source-specific PM2.5 concentrations.
UNASSIGNED: Using STEMI patients treated at the University of Rochester Medical Center, compositional and source-apportioned PM2.5 concentrations measured in Rochester, a time-stratified case-crossover design, and conditional logistic regression models, we estimated the rate of STEMI associated with increases in mean primary organic carbon (POC), secondary organic carbon (SOC), and source-specific PM2.5 concentrations on lag days 0, 0-3, and 0-6 during 2014-2019.
UNASSIGNED: The associations of an increased rate of STEMI with interquartile range (IQR) increases in spark-ignition emissions (GAS) and diesel (DIE) concentrations in the previous few days were not found from 2014 to 2019. However, IQR increases in GAS concentrations were associated with an increased rate of STEMI on the same day in the 2014-2016 period (Rate ratio [RR] = 1.69; 95% CI = 0.98, 2.94; 1.73 μg/m3). In addition, each IQR increase in mean SOC concentration in the previous 6 days was associated with an increased rate of STEMI, despite imprecision (RR = 1.14; 95% CI = 0.89, 1.45; 0.42 μg/m3).
UNASSIGNED: Increased SOC concentrations may be associated with increased rates of STEMI, while there seems to be a declining trend in adverse effects of GAS on triggering of STEMI. These changes could be attributed to changes in PM2.5 composition and sources following the Tier 3 vehicle introduction.

A few studies have explored the relationship between air pollution exposure and the risk of birth defects; however, the ozone-related (O3) effects on preconception and first-trimester exposures are still unknown. In this time-stratified case-crossover study, conditional logistic regressions were applied to explore the associations between O3 exposure and the risk of birth defects in Chongqing, China, and stratified analyses were constructed to evaluate the modifiable factors. A total of 6601 cases of birth defects were diagnosed, of which 56.16% were male. O3 exposure was associated with an increased risk of birth defects, and the most significant estimates were observed in the first month before pregnancy: a 10 ug/m3 increase of O3 was related to an elevation of 4.2% [95% confidence interval (CI), 3.4-5.1%]. The associations between O3 exposure and congenital malformations and deformations of the musculoskeletal system were statistically significant during almost all exposure periods. Pregnant women with lower education and income, and from rural areas, were more susceptible to O3 exposure, with the strongest odds ratios (ORs) of 1.066 (95%CI, 1.046-1.087), 1.086 (95%CI, 1.034-1.140), and 1.053 (95%CI, 1.034-1.072), respectively. Our findings highlight the health risks of air pollution exposure and raise awareness of pregnant women\'s vulnerability and the susceptibility window period.

Short-term exposure to ozone has been linked to multiple allergic diseases, but the relationship between ozone exposure and allergic conjunctivitis (AC) remains unclear. This study aimed to investigate the association between short-term exposure to ozone and the risk of AC. We conducted a time-stratified case-crossover study across five Chinese cities from 2014 to 2022. Daily outpatient visit records for AC were identified in five hospitals using either the diagnosis name or ICD-10 code H10.1. Data on air pollution and meteorological conditions were also collected. We first examined the city-specific association between short-term ozone exposure and AC using conditional logistic regression. A random-effects meta-analysis was then conducted to obtain overall estimates. During the study period, 130,093 outpatient visits for AC occurred, with 58.8% (76,482) being male and 41.2% (53,611) female. A one-standard-deviation (SD) increase in ozone was associated with an 8.3% increase (95% CI: 3.8%, 13.0%) in AC outpatient visits. Similar positive associations were observed when adjusting for other pollutants (PM2.5, CO, SO2 and NO2) in two-pollutant and multi-pollutant models. Furthermore, the positive association remained consistent when using mixed-effects regression models or further adjusting for meteorological conditions. In addition, no effect modification of the AC-ozone association by sex, age and season was apparent. This study provides evidence supporting a positive association between short-term ozone exposure and AC risk in China. This highlights the potential value of mitigating ozone pollution to reduce the risk of ocular surface disorders.

Racial/ethnic disparities in the association between short-term (e.g. days, weeks) ambient fine particulate matter (PM2.5) and temperature exposures and stillbirth in the US have been understudied. A time-stratified, case-crossover design using a distributed lag non-linear model (0 to 6-day lag) estimated stillbirth odds due to short-term increases in average daily PM2.5 and temperature exposures among 118,632 Medicaid recipients from 2000-2014. Disparities by maternal race/ethnicity (Black, White, Hispanic, Asian, American Indian) and zip-code level socioeconomic status (SES) were assessed. In the temperature-adjusted model, a 10 μg/m3 increase in PM2.5 concentration was marginally associated with increased stillbirth odds at lag 1 (0.68% 95%CI:[-0.04,1.40]) and lag 2 (0.52% 95%CI:[-0.03,1.06]), but not lag 0-6 (2.80% 95%CI:[-0.81,6.45]). An association between daily PM2.5 concentrations and stillbirth odds was found among Black individuals at the cumulative lag (0-6 days: 9.26% 95%CI:[3.12,15.77]), but not among other races/ethnicities. A stronger association between PM2.5 concentrations and stillbirth odds existed among Black individuals living in zip codes with the lowest median household income (lag0-6:14.13% 95%CI:[4.64,25.79]). Short-term temperature increases were not associated with stillbirth risk among any race/ethnicity. Black Medicaid enrollees, and especially those living in lower SES areas, may be more vulnerable to stillbirth due to short-term increases in PM2.5 exposure.

Fine particulate matter (PM2.5) is a risk factor of cardiovascular disease. Associations between PM2.5 compositions and cardiovascular disease are a point of special interest but inconsistent. This study aimed to explore the cardiovascular effects of heavy metal(loid) compositions in PM2.5. Data for mortality, air pollutants and meteorological factors in Anyang, China from 2017 to 2021 were collected. Heavy metal(loid) in PM2.5 were monitored and examined monthly. A Case-crossover design was applied to the estimated data set. The interquartile range increase in cadmium (Cd), antimony (Sb) and arsenic (As) at lag 1 was associated with increment of 8.1% (95% CI: 3.3, 13.2), 4.8% (95% CI: 0.2, 9.5) and 3.5% (95% CI: 1.1, 6.0) cardiovascular mortality. Selenium in lag 2 was inversely associated with cerebrovascular mortality (RR = 0.920 95% CI: 0.862, 0.983). Current-day exposure of aluminum was positively associated with mortality from ischemic heart disease (RR = 1.083 95% CI: 1.001, 1.172). Stratified analysis indicated sex, age and season modified the cardiovascular effects of As (P < 0.05). Our study reveals that heavy metal(loid) play key roles in adverse effects of PM2.5. Cd, Sb and As were significant risk factors of cardiovascular mortality. These findings have potential implications for accurate air pollutants control and management to improve public health benefits.

UNASSIGNED: There is an increasing body of evidence associating short-term ambient nitrogen dioxide (NO2) exposure with asthma-related hospital admissions in children. However, most studies have relied on temporally resolved exposure information, potentially ignoring the spatial variability of NO2. We aimed to investigate how daily NO2 estimates from a highly resolved spatio-temporal model are associated with the risk of emergency hospital admission for asthma in children in England.
UNASSIGNED: We conducted a time-stratified case-crossover study including 111,766 emergency hospital admissions for asthma in children (aged 0-14 years) between 1st January 2011 and 31st December 2015 in England. Daily NO2 levels were predicted at the patients\' place of residence using spatio-temporal models by combining land use data and chemical transport model estimates. Conditional logistic regression models were used to obtain the odds ratios (OR) and confidence intervals (CI) after adjusting for temperature, relative humidity, bank holidays, and influenza rates. The effect modifications by age, sex, season, area-level income deprivation, and region were explored in stratified analyses.
UNASSIGNED: For each 10 µg/m³ increase in NO2 exposure, we observed an 8% increase in asthma-related emergency admissions using a five-day moving NO2 average (mean lag 0-4) (OR 1.08, 95% CI 1.06-1.10). In the stratified analysis, we found larger effect sizes for male (OR 1.10, 95% CI 1.07-1.12) and during the cold season (OR 1.10, 95% CI 1.08-1.12). The effect estimates varied slightly by age group, area-level income deprivation, and region.
UNASSIGNED: Short-term exposure to NO2 was significantly associated with an increased risk of asthma emergency admissions among children in England. Future guidance and policies need to consider reflecting certain proven modifications, such as using season-specific countermeasures for air pollution control, to protect the at-risk population.

OBJECTIVE: The weather is frequently blamed for changes in musculoskeletal health behaviour and adverse events. However, despite the frequency with which this phenomenon is endorsed, past research is largely conflicting. This meta-analysis has reviewed, appraised and summarised case-crossover studies assessing the transient risk of musculoskeletal health events associated with weather parameters (e.g. temperature, relative humidity, air pressure, and precipitation).
METHODS: A meta-analysis of case-crossover studies was conducted. Two reviewers independently searched MEDLINE, EMBASE, CINAHL, Web of Science, Scopus, and PsycINFO from inception to 10/09/2023. Published studies that employed a case-crossover design to evaluate the risk of musculoskeletal health events (e.g. symptoms, hospitalisation) associated with weather parameters were included. Primary outcome was pain (new episodes of pain or flares). Quality of included studies was assessed based on selection bias, exposure assessment, confounding, and outcome assessment. Pooling of results was conducted using random effects models and separately performed for each condition and weather factor. Heterogeneity among included studies was assessed using I2 measures.
RESULTS: Of the 1,107 studies identified in the search, 11 were included (15,315 participants), providing data on 28,010 events (102,536 control periods), for seven musculoskeletal conditions. Pooled analyses showed no association between relative humidity, air pressure, temperature, or precipitation and the risk of rheumatoid arthritis, knee pain or low back pain. High temperatures combined with low humidity were associated with increased pain, redness, and joint swelling in people with gout (Odds Ratio: 2.04; 95 % Confidence Interval: 1.26 to 3.30).
CONCLUSIONS: Despite anecdotal reports from patients, changes in weather factors do not seem to be risk factors for rheumatoid arthritis, knee, hip, or low back pain, but may have a significant influence in gout disease.

Air pollution\'s short-term effects on a wide range of health outcomes have been studied extensively, primarily focused on vulnerable groups (e.g., children and the elderly). However, the air pollution effects on the adult working population through sick leave have received little attention. This study aims to 1) estimate the associations between particulate matter ≤2.5 μm3 (PM2.5) and sick leave episodes and 2) calculate the attributable number of sick leave days and the consequential productivity loss in the City of Stockholm, Sweden. Individual level daily sick leave data was obtained from Statistics Sweden for the years 2011-2019. Daily average concentrations of PM2.5 were obtained from the main urban background monitoring station in Stockholm. A case-crossover study design was applied to estimate the association between short-term PM2.5 and onset of sick leave episodes. Conditional logistic regression was used to estimate the relative increase in odds of onset per 10 μg/m3 of PM2.5, adjusting for temperature, season, and pollen. A human capital method was applied to estimate the PM2.5 attributable productivity loss. In total, 1.5 million (M) individual sick leave occurrences were studied. The measured daily mean PM2.5 concentration was 4.2 μg/m3 (IQR 3.7 μg/m3). The odds of a sick leave episode was estimated to increase by 8.5% (95% CI: 7.8-9.3) per 10 μg/m3 average exposure 2-4 days before. Sub-group analysis showed that private sector and individuals 15-24 years old had a lower increase in odds of sick leave episodes in relation to PM2.5 exposure. In Stockholm, 4% of the sick leave episodes were attributable to PM2.5 exposure, corresponding to €17 M per year in productivity loss. Our study suggests a positive association between PM2.5 and sick leave episodes in a low exposure area.

There is no intervention that quickly reduces a person\'s blood alcohol content (BAC). \"Sober up before you drive\" may prevent road traffic injury (RTI) caused by alcohol consumption. The aim of this study was to analyze the risk of RTI on an hourly basis (1-6 h) after the last drink and the determinants of this risk.
This was a case-crossover study of alcohol consumption among 430 patients who suffered an RTI and arrived at an emergency department in a large hospital in Mexico City from January to April 2022.
Of the 430 patients studied, 46 reported drinking within 1 h before the RTI, for a risk ratio (RR) of 7.7 (95% CI [5.6, 10.4]). This RR decreased to 2.2 (95% CI [1.3, 3.7]) for the 12 patients drinking in the second hour before the RTI and was null for those drinking earlier (p ≤ 0.001 for the trend). The induction time was 3 h among those with higher BAC and intoxication levels. The RR for an RTI decreases 71% from the first to second hour from the last drink and 32% from the second to third hour. This decrease was similar among those intoxicated and those with increased BACs. In multiple regression models, higher levels of intoxication and higher BACs remained associated with higher RRs.
People should avoid driving after drinking. Waiting to drive, walking, or riding after drinking reduces the risk of an RTI, especially for people with higher BAC and intoxication levels.

Air pollution poses a threat to children\'s respiratory health. This study aims to quantify the association between short-term air pollution exposure and respiratory hospital admissions among children in Hanoi, Vietnam, and estimate the population-attributable burden using local data. A case-crossover analysis was conducted based on the individual records where each case is their own control. The health data was obtained from 13 hospitals in Hanoi and air pollution data was collected from four monitoring stations from 2007 to 2019. We used conditional logistic regression to estimate Percentage Change (PC) and 95% Confidence Interval (CI) in odd of hospital admissions per 10 μg/m3 increase in daily average particulate matter (e.g. PM1, PM2.5, PM10), Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2), 8-h maximum Ozone and per 1000 μg/m3 increase in daily mean of Carbon Monoxide (CO). We also calculated the number and fraction of admissions attributed to air pollution in Hanoi by using the coefficient at lag 0. A 10 μg/m3 increase in the concentration of PM10, PM2.5, PM1, SO2, NO2, O3 8-h maximum and 1000 μg/m3 increase in CO concentration was associated with 0.6%, 1.2%, 1.4%, 0.8%, 1.6%, 0.3%, and 1.7% increase in odd of admission for all respiratory diseases among children under 16 years at lag 0-2. All PM metrics and NO2 are associated with childhood admission for pneumonia and bronchitis. Admissions due to asthma and upper respiratory diseases are related to increments in NO2 and CO. For attributable cases, PM2.5 concentrations in Hanoi exceeding the World Health Organization Air Quality Guidelines accounted for 1619 respiratory hospital admissions in Hanoi children in 2019. Our findings show that air pollution has a detrimental impact on the respiratory health of Hanoi children and there will be important health benefits from improved air quality management planning to reduce air pollution in Vietnam.