An association between fine particulate matter (PM2.5) levels and emergency ambulance dispatches for cardiovascular diseases in Japan

Association between daily circulatory emergency ambulance dispatches and short-term PM2.5 exposure in a heavily polluted area

Emergency ambulance dispatches (EAD) have been proven to be associated with ambient particulate matter with diameter < 2.5 μm (PM2.5) concentration, but the associations of circulatory EAD remained inconclusive, especially in heavily polluted areas. In this time series conducted in Shenyang City, Northeastern China, we explored the associations between circulatory EAD and ambient PM2.5 and its constituents. Data including 113,508 circulatory EAD records, five types of PM2.5 constituents, and meteorological information spanning from 2014 to 2019 were retrieved. Using generalized additive models (GAMs), we explored the association between circulatory EAD and calculated excess risks induced by a 10 μg/m3 increase (ERR10) in PM2.5 mass and its constituents. ERR by percentage change (ERRpc) to compare among the different constituents were also calculated. Positive associations between circulatory EAD and PM2.5 mass, sulfates, organic matters, and black carbon, were found particularly at lag0 and lag0-5, with the ERR10 of 3.8% (3.2%-4.4%), 6.5% (2.2%-10.8%), 4.2% (1.7%-6.6%), and 30.2% (17.2%-43.4%) at lag0-5, respectively. Similar associations were observed for cardiovascular EAD, while cerebrovascular EAD suggested a positive association with O3 rather than PM2.5 or its constituents. Notably, PM2.5 mass exhibited the largest ERRpc for circulatory and cardiovascular EAD, followed by sulfates and black carbon. Moreover, the risks were enhanced for circulatory and cardiovascular EAD in males compared to females and during warmer seasons compared to colder seasons. Our findings contribute new evidence on PM2.5 exposure and circulatory EAD in relatively polluted areas.

The Combined Effects of Hourly Multi-Pollutant on the Risk of Ambulance Emergency Calls: A Seven-Year Time Series Study

BACKGROUND

Ambulance emergency calls (AECs) are seen as a more suitable metric for syndromic surveillance due to their heightened sensitivity in reflecting the health impacts of air pollutants. Limited evidence has emphasized the combined effect of hourly air pollutants on AECs. This study aims to investigate the combined effects of multipollutants (i.e., PM2.5, PM10, Ozone, NO2, and SO2) on all-cause and cause-specific AECs by using the quantile g-computation method.

METHODS

We used ambulance emergency dispatch data, air pollutant data, and meteorological data from between 1 January 2013 and 31 December 2019 in Shenzhen, China, to estimate the associations of hourly multipollutants with AECs. We followed a two-stage analytic protocol, including the distributed lag nonlinear model, to examine the predominant lag for each air pollutant, as well as the quantile g-computation model to determine the associations of air pollutant mixtures with all-cause and cause-specific AECs.

RESULTS

A total of 3,022,164 patients were identified during the study period in Shenzhen. We found that each interquartile range increment in the concentrations of PM2.5, PM10, Ozone, NO2, and SO2 in 0-8 h, 0-8 h, 0-48 h, 0-28 h, and 0-24 h was associated with the highest risk of AECs. Each interquartile range increase in the mixture of air pollutants was significantly associated with a 1.67% (95% CI, 0.12-3.12%) increase in the risk of all-cause AECs, a 1.81% (95% CI, 0.25-3.39%) increase in the risk of vascular AECs, a 1.77% (95% CI, 0.44-3.11%) increase in reproductive AECs, and a 2.12% (95% CI, 0.56-3.71%) increase in AECs due to injuries.

CONCLUSIONS

We found combined effects of pollutant mixtures associated with an increased risk of AECs across various causes. These findings highlight the importance of targeted policies and interventions to reduce air pollution, particularly for PM, Ozone, and NO2 emissions.

Relationship between diurnal temperature range and emergency ambulance dispatches due to stroke in Guangzhou, China

BACKGROUND

The evidence between diurnal temperature range (DTR) and stroke remains controversial and sparse. We aimed to assess the relationship between DTR and emergency ambulance dispatches (EADs) due to stroke, and to explore whether there were effect modifications to the relationship.

METHODS

A Quasi-Poisson generalized linear regression combined with a distributed lag non-linear model was used to examine the relationship between DTR and EADs for stroke between January 1st 2011 and June 30th 2018 in Guangzhou, China. We estimated the effects of the low DTR and high DTR (defined as DTR below and above 10 °C respectively) on EADs. The effects of minimum, maximum, 5th, 25th, 50th, 75th, and 95th percentiles of DTR compared with the DTR of 10 °C were also analyzed.

RESULTS

A total of 20,275 EADs for stroke were included for analyses, among which 17,556 EADs were used in the model further adjusted for age and sex. A quasi-U-shaped relationship between DTR and EADs over lag0-2 days was observed. For the low DTR, per 1 °C decrease in DTR was significantly associated with an increase of 2.64% (RR = 1.03, 95% CI: 1.01-1.04) for EADs, while per 1 °C increase for the high DTR was non-significantly related with an increased risk of EADs (RR = 1.01, 95% CI: 0.90-1.13). Significant effects of the 5th and 25th percentiles of DTR on EADs were found when compared with the DTR of 10 °C. No significant effect modifications by age, sex or season were found to the association between DTR and EADs.

CONCLUSIONS

We found a quasi-U-shaped relationship between DTR and EADs due to stroke in this study, while age, sex or season did not significantly modify the association between DTR and EADs. More high-quality evidence is needed to further explore and validate the relationship between DTR and stroke.

Long-term impact of exposure to coalmine fire emitted PM2.5 on emergency ambulance attendances

BACKGROUND

Little is known about the long-term health effects of coalmine fire smoke exposure. The 2014 Hazelwood coalmine fire event in southeast Australia released smoke into surrounding areas for 6 weeks.

OBJECTIVES

We aimed to investigate whether individual-level exposure to coalmine fire-related PM_2.5 was associated with a long-term increase in ambulance attendances following a coalmine fire event.

METHODS

A total of 2223 residents from the most exposed town of Morwell were assessed for ambulance attendances after the Hazelwood event from April 1, 2014 to December 31, 2017. PM_2.5 exposure was estimated for each individual using participant self-reported location diary data during the event and modelled PM_2.5 concentrations. Recurrent event survival analysis was used to evaluate the relationship between PM_2.5 exposure and ambulance attendances.

RESULTS

For each 10 μg/m³ increase in mean coalmine fire-related PM_2.5 exposure, there was a 10% (adjusted hazard ratio [HR]:1.10, 95%CI:1.03-1.17) increase in the overall risk of ambulance attendances within 3.5 years after the coalmine fire. Exposure to PM_2.5 was also associated with increased risk of respiratory (HR: 1.21, 95%CI: 1.02-1.44) and cardiovascular (HR: 1.13, 95%CI: 1.01-1.28) related ambulance attendances.

CONCLUSION

These results demonstrate that exposure to coalmine fire smoke during the Hazelwood event was associated with a long-term health risk post the fire event, specifically for respiratory and cardiovascular conditions. These findings are important for effective implementation of health care services following future extended coalmine fire PM_2.5 events.

Relationship between different air pollutants and total and cause-specific emergency ambulance dispatches in Shanghai, China

OBJECTIVE

Air pollutants play a crucial role in human health and disease. Emergency ambulance dispatch data have excellent potential for public and environmental health research. This study aimed at investigating the impact of short-term exposure to air pollutants on the emergency ambulance dispatches.

METHODS

We used data on emergency ambulance dispatches in Shanghai Municipality, China, from April 1, 2016 to December 31, 2017. The association of the daily emergency ambulance dispatches with air pollutants including PM_2.5 (particles ≤ 2.5 μm in aerodynamic diameter), PM₁₀, O₃, NO₂ and SO₂ was analyzed with the use of time-series analyses.

RESULTS

A total of 310,825 emergency ambulance dispatches for acute illness occurred in Shanghai during the study period. An increase in PM_2.5 by 10 μg/m³ at lag1 and lag2 was shown to increase the risk of emergency ambulance dispatches (RR for lag1 = 1.05, 95% CI 1.00-1.11, RR for lag2 = 1.07, 95% CI 1.01-1.12). PM₁₀, NO₂, and SO₂ also showed significant associations with emergency ambulance dispatches in single-pollutant models. Cause-specific analyses showed an elevation in PM_2.5 by 10 μg/m³ was associated with an increased risk of emergency ambulance dispatches related to respiratory diseases on the current day (lag0, RR 1.17, 95% CI 1.01-1.33), while the impact on emergency ambulance dispatches related to other diseases presented 1-3 days later. The other pollutants have the similar trend.

CONCLUSIONS

Our findings show a strong relationship between ambient air pollutants and emergency ambulance dispatches. Our study contributes to the growing body of evidence describing the adverse health effects of ambient air pollution and will benefit ambulance services for early warning and effective ambulatory planning.

Fine particles in surgical smoke affect embryonic cardiomyocyte differentiation through oxidative stress and mitophagy

Surgical smoke is widespread in operating rooms, and fine particles are the main toxic components. However, the effect of fine particles in surgical smoke on embryonic development has not yet been studied. This study evaluated the effect of fine particles in surgical smoke on embryonic development and compared it with that of atmospheric fine particles. Afterwards, differentiated cardiomyocytes were purified, and the effect of exposure to fine particles in surgical smoke on cardiomyocyte differentiation was evaluated. Fine particles in surgical smoke exhibited weak embryotoxicity toward an embryonic stem cell test model, and their inhibitory effect on cardiomyocyte differentiation was slightly stronger than that of atmospheric fine particles. Fine particles in surgical smoke specifically inhibited the differentiation of the mesoderm lineage and promoted the differentiation of the ectoderm lineage. Furthermore, fine particles in surgical smoke reduced the beating rate of purified cardiomyocytes, promoted mitophagy, reduced ATP production and increased the reactive oxygen species (ROS) content. Antioxidants attenuated the inhibition of cardiomyocyte differentiation and the reduction in the cardiomyocyte beating rate caused by fine particles in surgical smoke and simultaneously restored mitophagy and other processes to the control levels. However, mitophagy inhibitors treatment blocked only the inhibition of cardiomyocyte differentiation caused by fine particles in surgical smoke; it had little effect on other changes caused by fine particles. Based on the results described above, we propose that fine particles in surgical smoke and atmospheric fine particles exhibit similar levels of toxicity toward embryonic development. Fine particles in surgical smoke potentially affect the beating of cardiomyocytes by damaging mitochondria and increasing oxidative stress.

Effects of hourly levels of ambient air pollution on ambulance emergency call-outs in Shenzhen, China

Some researches have shown the associations between air pollution and hospital-based emergency department visits, while the evidence about the acute effects of air pollution on emergency ambulance dispatches for the whole population is rarely available, especially on an hourly time scale. This paper aimed to investigate the effects of hourly concentrations of ambient air pollution on hourly number of ambulance emergency call-outs (AECOs) in Shenzhen, China. AECO data were collected from Shenzhen Emergency Center from January 2013 to December 2016. A time-stratified case-crossover design with conditional Poisson regression was performed to fit the relationship between hourly air pollution and AECOs. The distributed lag model was applied to determine lag structure of the effects of air pollutants. There were a total of 502,862 AECOs during the study period. The significant detrimental effects of SO₂, PM_2.5, and PM₁₀ appeared immediately with a following harvesting effect after 5 h and the effects lasted for about 96 h. The cumulative effect estimates of four pollutants over 0-96 h were 13.99% (95% CI 7.52-20.85%), 2.07% (95% CI 0.72-3.43%), 1.20% (95% CI 0.54-1.87%), and 2.46% (95% CI 1.63-3.29%), respectively. We did not observe significant effects of O₃. This population-based study quantifies the adverse effects of air pollution on ambulance dispatches and provides evidence of the lag structure of the effects on an hourly time scale.

Relationship between different particle size fractions and all-cause and cause-specific emergency ambulance dispatches

BACKGROUND

Evidence on the relationship between different particle size fractions and emergency ambulance dispatches (EAD) remains limited and sparse.

METHODS

We collected daily data of EAD, ambient air pollution and meteorological data from 2014 to 2018 in Guangzhou, China. We used a generalized additive model with covariate adjustments to estimate the associations between different particle size fractions and EAD related to all-cause, cardiovascular diseases, and respiratory diseases. Several subgroup and sensitivity analyses were also performed.

RESULTS

Significant associations were observed between PM_2.5, PM_2.5-10, PM₁₀ and EADs. A 10 μg/m³ increase of PM_2.5, PM_2.5-10, and PM₁₀ was associated with an increase of 0.98% (95% CI: 0.67, 1.28%), 2.06% (95% CI: 1.44, 2.68%), and 0.75% (95%CI: 0.53, 0.96%) in all-cause EAD, with an increase of 0.69% (95% CI: 0.00, 1.39%), 2.04% (95% CI: 0.64, 3.45%), and 0.60% (95%CI: 0.11,1.10%) in cardiovascular-related EAD, and an increase of 1.14% (95% CI: 0.25, 2.04%), 2.52% (95% CI: 0.72, 4.35%), and 0.89% (95%CI: 0.25,1.52%) in respiratory-related EAD at lag03, respectively. The results were robust in subgroup and sensitivity analyses.

CONCLUSIONS

This study revealed that PM_2.5, PM_2.5-10 and PM₁₀ were significantly related with risks of all-cause and cause-specific EAD. More evidence of high quality may be needed to further support our results in this ecological study.

The impact of air pollutants on ambulance dispatches: A systematic review and meta-analysis of acute effects

A number of systematic reviews have investigated the association between air pollutants and health impacts, these mostly focus on morbidity and mortality from hospital data. Previously, no reviews focused solely on ambulance dispatch data. These data sets have excellent potential for environmental health research. For this review, publications up to April 2019 were identified using three main search categories covering: ambulance services including dispatches; air pollutants; and health outcomes. From 308 studies initially identified, 275 were excluded as they did not relate to ambulance service dispatches, did not report the air pollutant association, and/or did not study ambient air pollution. The main health outcomes in the remaining 33 studies were cardiac arrest (n = 14), cardiovascular (n = 11) and respiratory (n = 10) dispatches. Meta-analyses were performed to summarise pooled relative risk (RR) of pollutants: particulate matter less than 2.5 and 10 μm (PM_2.5, PM₁₀), the fraction between PM₁₀ and PM_2.5 (coarse) and suspended particulate matter (SPM) per 10 μg/m³ increase, carbon monoxide (CO) per 1 ppm increase and of sulphur dioxide (SO₂), nitrogen dioxide (NO₂), and ozone (O₃) per 10 ppb increment and ambulance dispatches. Statistically significant associations were found for ambulance dispatch data for all-respiratory and PM_2.5 at 1.03 (95% CI:1.02-1.04) and at 1.10 (95% CI:1.00-1.21) for asthma and NO₂ associations. For dispatches with subsequent paramedic assessment for cardiac arrest with PM_2.5, CO and coarse dispatches at 1.05 (95% CI:1.03-1.08), 1.10 (95% CI:1.02-1.18) and 1.04 (95% CI:1.01-1.06) respectively. For dispatches with subsequent physician diagnosis for all-respiratory and PM_2.5 at 1.02 (95% CI:1.01-1.03). In conclusion, air pollution was significantly associated with an increase in ambulance dispatch data, including those for cardiac arrest, all-respiratory, and asthma dispatches. Ambulance services should plan accordingly during pollution events. Furthermore, efforts to improve air quality should lead to decreases in ambulance dispatches.

Ambient fine particulate matter is associated with increased emergency ambulance dispatches for psychiatric emergencies

AIMS

As a top ambient pollutant in urban area, fine particulate matter (PM_2.5) has been associated with the occurrence and deterioration of many medical conditions, while limited studies have observed the association with psychiatric conditions. This study aimed to investigate the association between short-term PM_2.5 exposure and psychiatric emergency events, and further explored the variation by age, sex and seasonal patterns, which have been suggested to be associated with both psychiatric risk and pollutant toxicity.

METHODS

We used time-series analysis to investigate the association between short-term exposure of PM_2.5 and emergency ambulance dispatches for psychiatric emergencies (EPE) (n = 158634) in Beijing, one of the top polluted cities in China during the study period between 2008 and 2014. Stratified analyses were conducted to examine the effects of age, sex and seasonal pattern.

RESULTS

Every 10 μg/m³ increase of the PM_2.5 concentration was associated with a 0.12% increase of the same-day overall EPE (95% CI: 0.03-0.22%, p = 0.013) and a 0.12% increase of the suicide-related EPE at lag 2 (95%CI: 0.01-0.24%, p = 0.041). The associations remained when adjusted for sunlight duration. An age effect was observed where children (age <18) showed a higher risk of suicide-related EPE after PM_2.5 exposure compared to adults (18 ≤ age≤64). We did not observe evidence of effect modification by sex and season based on the results of stratified analysis.

CONCLUSIONS

We found a positive association between acute PM_2.5 exposure and increased psychiatric emergency presentations indicated by emergency ambulance dispatches data. Children were more vulnerable and might develop psychiatric problems including those leading to suicide. Public awareness of the health risks of PM_2.5 is important to strengthen current efforts to reduce emissions.

The relationship between fine particulate matter (PM2.5) and schizophrenia severity

PURPOSE

Although particulate matter (PM) is reported to affect the rate of emergency admissions for schizophrenia, no study has examined the relationship between particulate matter less than 2.5 μm in diameter (PM_2.5) and the severity of schizophrenia.

METHODS

We obtained data on patients with schizophrenia at a psychiatric hospital, and on air pollution in Sakai, Japan between Feb 1, 2013 and April 30, 2016. Multivariate logistic regression analyses were used to estimate the relationship between PM_2.5 concentrations and scores on the Brief Psychiatric Rating Scale (BPRS) of schizophrenia patients at admission, with a lag of up to 7 days.

RESULTS

During the study period, there were 1193 schizophrenia cases. The odds ratio (OR) for a BPRS score ≥ 50 at admission was 1.05 [95% confidence interval 1.00-1.10] and the effect of PM_2.5 concentration was significant for lag period of 2 days. The ORs associated with PM_2.5 concentration increased substantially for patients over 65 years of age.

CONCLUSIONS

Ambient PM_2.5 concentration was associated with exacerbation of schizophrenia. Our results suggest that protection for several days should be considered for controlling PM_2.5-related schizophrenia, especially among elderly patients.

Acute Effects of Ambient PM2.5 on All-Cause and Cause-Specific Emergency Ambulance Dispatches in Japan

Short-term health effects of ambient PM_2.5 have been established with numerous studies, but evidence in Asian countries is limited. This study aimed to investigate the short-term effects of PM_2.5 on acute health outcomes, particularly all-cause, cardiovascular, respiratory, cerebrovascular and neuropsychological outcomes. We utilized daily emergency ambulance dispatches (EAD) data from eight Japanese cities (2007–2011). Statistical analyses included two stages: (1) City-level generalized linear model with Poisson distribution; (2) Random-effects meta-analysis in pooling city-specific effect estimates. Lag patterns were explored using (1) unconstrained-distributed lags (lag 0 to lag 7) and (2) average lags (lag: 0–1, 0–3, 0–5, 0–7). In all-cause EAD, significant increases were observed in both shorter lag (lag 0: 1.24% (95% CI: 0.92, 1.56)) and average lag 0–1 (0.64% (95% CI: 0.23, 1.06)). Increases of 1.88% and 1.48% in respiratory and neuropsychological EAD outcomes, respectively, were observed at lag 0 per 10 µg/m³ increase in PM_2.5. While respiratory outcomes demonstrated significant average effects, no significant effect was observed for cardiovascular outcomes. Meanwhile, an inverse association was observed in cerebrovascular outcomes. In this study, we observed that effects of PM_2.5 on all-cause, respiratory and neuropsychological EAD were acute, with average effects not exceeding 3 days prior to EAD onset.

Associations of short-term exposure to ambient air pollutants with emergency ambulance calls for the exacerbation of essential arterial hypertension

We investigated the association between daily emergency ambulance calls (EAC) for elevated blood pressure that occurred during the time intervals of 8:00-13:59, 14:00-21:59, and 22:00-7:59, and exposure to CO, PM₁₀, and ozone. We used Poisson regression to explore the association between the risk of EAC and short-term variation of pollutants, adjusting for seasonality and weather variables. Before noon, the risk was associated with an interquartile range (IQR) (7.9 μg/m³) increase in PM₁₀ at lag 2-4 days below the median (RR = 1.08, p = 0.031) and with an IQR (0.146 mg/m³) increase in CO at lag 6-7 below the median (RR = 1.05, p = 0.028). During 14:00-21:59, the risk was associated with an IQR (18.8 μg/m³) increase in PM₁₀ on the previous day below the median (RR = 1.04, p = 0.031). At night, EAC were negatively affected by lower O₃ (lag 0-2) below the median (per IQR decrease RR = 1.10, p = 0.018) and a higher PM₁₀ at lag 0-1 above the median for the elderly (RR = 1.07, p = 0.030).

The relationship between airborne fine particle matter and emergency ambulance dispatches in a southwestern city in Chengdu, China

High levels of fine particulate matter (PM_2.5) are known to cause adverse effects to human health. The goal of this study was to estimate the acute health effects of short-term exposure to ambient PM_2.5 by analyzing cause-specific emergency ambulance dispatches as the endpoint in Chengdu, a city in Sichuan Province in southwest China. The ambient PM_2.5 concentration of Chengdu reached 63 μg/m³ in 2015. Data related to the causes of specific emergency ambulance dispatches, air pollution, and meteorological conditions were collected from 2013 to 2015 (1095 days). A generalized additive model (GAM) was constructed to control the confounding conditions and to estimate the effects of PM_2.5 on human health conditions. Emergency ambulance dispatches for all causes with (RR for lag0 = 1.0010, 95%CI: 1.0002, 1.0019) or without injuries (RR for lag0 = 1.0012, 95%CI: 1.0002, 1.0022), respiratory diseases (RR for lag0 = 1.0051, 95%CI: 1.0012, 1.0089), and cardiovascular diseases (RR for lag0 = 1.0041, 95%CI: 1.0009, 1.0074) were associated with ambient PM_2.5 concentrations in Chengdu. In addition, the effects of PM_2.5 were not confounded by ozone.