Age- and season-specific effects of ambient particles (PM1, PM2.5, and PM10) on daily emergency department visits among two Chinese metropolitan populations

How long-term PM exposure may affect all-site cancer mortality: Evidence from a large cohort in southern China

BACKGROUND

Evidence of a potential causal link between long-term exposure to particulate matter (PM) and all-site cancer mortality from large population cohorts remained limited and suffered from residual confounding issues with traditional statistical methods.

AIMS

We aimed to examine the potential causal relationship between long-term PM exposure and all-site cancer mortality in South China using causal inference methods.

METHODS

We used a cohort in southern China that recruited 580,757 participants from 2009 through 2015 and tracked until 2020. Annual averages of PM1, PM2.5, and PM10 concentrations were generated with validated spatiotemporal models. We employed a causal inference approach, the Marginal Structural Cox model, based on observational data to evaluate the association between long-term exposure to PM and all-site cancer mortality.

RESULTS

With an increase of 1 µg/m³ in PM1, PM2.5, and PM10, the hazard ratios (HRs) and 95% confidence interval (CI) for all-site cancer were 1.033 (95% CI: 1.025-1.041), 1.032 (95% CI: 1.027-1.038), and 1.020 (95% CI: 1.016-1.025), respectively. The HRs (95% CI) for digestive system and respiratory system cancer mortality associated with each 1 µg/m³ increase in PM1 were 1.022 (1.009-1.035) and 1.053 (1.038-1.068), respectively. In addition, inactive participants, who never smoked, or who lived in areas of low surrounding greenness were more susceptible to the effects of PM exposure, the HRs (95% CI) for all-site cancer mortality were 1.042 (1.031-1.053), 1.041 (1.032-1.050), and 1.0473 (1.025-1.070) for every 1 µg/m³ increase in PM1, respectively. The effect of PM1 tended to be more pronounced in the low-exposure group than in the general population, and multiple sensitivity analyses confirmed the robustness of the results.

CONCLUSION

This study provided evidence that long-term exposure to PM may elevate the risk of all-site cancer mortality, emphasizing the potential health benefits of improving air quality for cancer prevention.

Contrasting Health Outcomes following a Severe Smoke Episode and Ambient Air Pollution in Early Life: Findings from an Australian Data Linkage Cohort Study of Hospital Utilization

BACKGROUND

Episodic spikes in air pollution due to landscape fires are increasing, and their potential for longer term health impacts is uncertain.

OBJECTIVE

Our objective is to evaluate associations between exposure in utero and in infancy to severe pollution from a mine fire, background ambient air pollution, and subsequent hospital care.

METHODS

We linked health records of births, emergency department (ED) visits, and hospitalizations of children born in the Latrobe Valley, Australia, 2012-2015, which included a severe pollution episode from a mine fire (9 February 2014 to 25 March 2014). We assigned modeled exposure estimates for fire-related and ambient particulate matter with an aerodynamic diameter of 2.5 μ m (PM 2.5 ) to residential address. We used logistic regression to estimate associations with hospital visits for any cause and groupings of infectious, allergic, and respiratory conditions. Outcomes were assessed for the first year of life in the in utero cohort and the year following the fire in the infant cohort. We estimated exposure-response for both fire-related and ambient PM 2.5 and also employed inverse probability weighting using the propensity score to compare exposed and not/minimally exposed children.

RESULTS

Prenatal exposure to fire-related PM 2.5 was associated with ED presentations for allergies/skin rash [odds ratio ( OR ) = 1.34 , 95% confidence interval (CI): 1.01, 1.76 per 240   μ g / m 3 increase]. Exposure in utero to ambient PM 2.5 was associated with overall presentations (OR = 1.18 , 95% CI: 1.05, 1.33 per 1.4   μ g / m 3 ) and visits for infections (ED: OR = 1.13 , 95% CI: 0.98, 1.29; hospitalizations: OR = 1.23 , 95% CI: 1.00, 1.52). Exposure in infancy to fire-related PM 2.5 compared to no/minimal exposure, was associated with ED presentations for respiratory (OR = 1.37 , 95% CI: 1.05, 1.80) and infectious conditions (any: OR = 1.21 , 95% CI: 0.98, 1.49; respiratory-related: OR = 1.39 , 95% CI: 1.05, 1.83). Early life exposure to ambient PM 2.5 was associated with overall ED visits (OR = 1.17 , 95% CI: 1.05, 1.30 per 1.4   μ g / m 3 increase).

DISCUSSION

Higher episodic and lower ambient concentrations of PM 2.5 in early life were associated with visits for allergic, respiratory, and infectious conditions. Our findings also indicated differences in associations at the two developmental stages. https://doi.org/10.1289/EHP12238.

Short-Term Effect of Moderate Level Air Pollution on Outpatient Visits for Multiple Clinic Departments: A Time-Series Analysis in Xi'an China

There is limited evidence concerning the association between air pollution and different outpatient visits in moderately polluted areas. This paper investigates the effects of moderate-level air pollution on outpatient visits associated with six categories of clinic department. We analyzed a total of 1,340,791 outpatient visits for the pediatric, respiratory, ear-nose-throat (ENT), cardiovascular, ophthalmology, and orthopedics departments from January 2016 to December 2018. A distributed lag nonlinear model was used to analyze the associations and was fitted and stratified by age and season (central heating season and nonheating season). We found SO2 had the largest effect on pediatrics visits (RR = 1.105 (95%CI: 1.090, 1.121)). Meanwhile, PM2.5 and SO2 had greater effects on ENT visits for people under 50 years old. The results showed a strong association between O3 and cardiovascular outpatient visits in the nonheating season (RR = 1.273, 95% CI: 1.189,1.358). The results showed every 10 μg/m3 increase in SO2 was associated with a lower number of respiratory outpatient visits. Significant different associations were observed in PM2.5, NO2, CO, and O3 on ophthalmology visits between the heating and nonheating seasons. Although no significant association has been found in existing studies, our findings showed PM2.5 and NO2 were significantly related to orthopedic outpatient visits for people under 60 (RR = 1.063 (95%CI: 1.032, 1.095), RR = 1.055 (95%CI: 1.011, 1.101)). This study also found that the effect-level concentrations of air pollutants for some clinic departments were lower than the national standards, which means that people should also pay more attention when the air quality is normal.

Differential effects of size-specific particulate matter on the number of visits to outpatient fever clinics: A time-series analysis in Zhuhai, China

Introduction

While many studies have investigated the adverse effects of particulate matter (PM), few of them distinguished the different effects of PM_2.5, PM₁₀, and coarse PM (PMc) on outpatients with fever. Our study aimed to estimate and compare the acute cumulative effects of exposure to three size-specific particles on the number of visits to outpatient fever clinics.

Methods

To examine the association between daily PM concentrations and outpatients in fever clinics, a generalized additive Poisson model was applied, stratified by sex, age, and season.

Results

Our study included 56,144 outpatient visits in Zhuhai, from January 2020 to June 2021. On the current day, each 10 mg/m³ increment of PM₁₀ and PMc were estimated to increase fever clinic visits by 1.74% (95% CI: 0.59%, 2.91%) and 4.42 % (2.30%, 6.58%), respectively. Cumulative effects enhanced from lag01 to lag05 for PM₁₀ and PMc, and PMc had the strongest impact [ER = 8.92% (5.91%, 12.01%) at lag05]. Female outpatients and outpatients aged 14 years and above had an increased PM-related risk. During the cold season, significant effects could be observed for the three-size PM, while only PMc showed the impact during the warm season.

Discussion

Overall, the three size-specific PM exerted different effects on the fever clinic visits. Strategies to control the concentrations of PM are still necessary, especially against PM₁₀ and PMc.

A comparison of fine particulate matter (PM2.5) in vivo exposure studies incorporating chemical analysis

The complex, variable mixtures present in fine particulate matter (PM_2.5) have been well established, and associations between chemical constituents and human health are expanding. In the past decade, there has been an increase in PM_2.5 toxicology studies that include chemical analysis of samples. This investigation is a crucial component for identifying the causal constituents for observed adverse health effects following exposure to PM_2.5. In this review, investigations of PM_2.5 that used both in vivo models were explored and chemical analysis with a focus on respiratory, cardiovascular, central nervous system, reproductive, and developmental toxicity was examined to determine if chemical constituents were considered in the interpretation of the toxicity findings. Comparisons between model systems, PM_2.5 characteristics, endpoints, and results were made. A vast majority of studies observed adverse effects in vivo following exposure to PM_2.5. While limited, investigations that explored connections between chemical components and measured endpoints noted significant associations between biological measurements and a variety of PM_2.5 constituents including elements, ions, and organic/elemental carbon, indicating the need for such analysis. Current limitations in available data, including relatively scarce statistical comparisons between collected toxicity and chemical datasets, are provided. Future progress in this field in combination with epidemiologic research examining chemical composition may support regulatory standards of PM_2.5 to protect human health.

Association of short-term exposure to air pollution with emergency visits for respiratory diseases in children

Ambient air pollutants are health hazards to children. This study comprised 773,504 emergency department visits (EDVs) at 0–14 years of age with respiratory diseases in southern China. All air pollutants were positively associated with EDVs of total respiratory diseases, especially pneumonia. NO₂, PM₁₀, and PM_2.5 had intraday effects and cumulative effects on asthma EDVs. The effect of SO₂, PM₁₀, and PM_2.5 on pneumonia EDVs was stronger in girls than in boys. The effect of NO₂ on acute upper respiratory tract infection EDVs was greater in children aged 0–5 years old; however, the effect of PM₁₀ on acute upper respiratory tract infection EDVs was greater in the 6–14 years group. In a two-pollutant model, NO₂ was associated with bronchitis and pneumonia, and PM₁₀ was associated with acute upper respiratory tract infection. In this time-series study, NO₂ and PM₁₀ were risk indicators for respiratory diseases in children.

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Air pollution associates with children emergency visits for respiratory diseases

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NO₂ and PM₁₀ are risk indicators for respiratory diseases in children

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Young children are more sensitive to gaseous pollutants

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School-age children are more sensitive to PM₁₀

Maternal exposure to traffic-related ambient particles and risk of gestational diabetes mellitus with isolated fasting hyperglycaemia: A retrospective cohort study in Beijing, China

BACKGROUND

Ambient particles have been associated with gestational diabetes mellitus (GDM), however, no study has evaluated the effects of traffic-related ambient particles on the risks of GDM subgroups classified by oral glucose tolerance test (OGTT) values.

METHODS

A retrospective analysis was conducted among 24,001 pregnant women who underwent regular prenatal care and received OGTT at Haidian Maternal and Child Health Hospital in Beijing, China, 2014-2017. A total of 3,168 (13.2%) pregnant women were diagnosed with GDM, including 1,206 with isolated fasting hyperglycaemia (GDM-IFH). At a fixed-location monitoring station, routinely monitored ambient particles included fine particulate matter (PM_2.5), black carbon (BC) and particles in size ranges of 5-560 nm (PNC_5-560). Contributions of PNC_5-560 sources were apportioned by positive matrix factorization model. Logistic regression model was applied to estimate odds ratio (OR) of ambient particles on GDM risk.

RESULTS

Among the 24,001 pregnancy women recruited in this study, 3,168 (13.2%) were diagnosed with GDM, including 1,206 with isolated fasting hyperglycaemia (GDM-IFH) and 1,295 with isolated post-load hyperglycaemia (GDM-IPH). We observed increased GDM-IFH risk with per interquartile range increase in first-trimester exposures to PM_2.5 (OR = 1.94; 95% Confidence Intervals: 1.23-3.07), BC (OR = 2.14; 1.73-2.66) and PNC_5-560 (OR = 2.46; 1.90-3.19). PNC_5-560 originated from diesel and gasoline vehicle emissions were found in associations with increases in GDM-IFH risk, but not in GDM-IPH risk.

CONCLUSION

Our findings suggest that exposure to traffic-related ambient particles may increase GDM risk by exerting adverse effects on fasting glucose levels during pregnancy, and support continuing efforts to reduce traffic emissions for protecting vulnerable population who are at greater risk of glucose metabolism disorder.

Differential associations of particle size ranges and constituents with stroke emergency-room visits in Shanghai, China

BACKGROUND AND PURPOSE

Fine particulate matter (PM_2.5) has been associated with increased risks of stroke, but it remains unclear which specific size ranges and chemical constituents dominate the effects of PM_2.5 on stroke. We aimed to evaluate the associations of size-segregated particles and various constituents of PM_2.5 with daily emergency-room visits for stroke.

METHODS

We conducted a time-series study to investigate the associations of 5 particle size ranges from 0.01 to 2.5 µm and 35 constituents of PM_2.5 with the daily emergency-room visits for stroke in Shanghai, from 2014 to 2019. Over-dispersed generalized additive models were used to estimate the associations. The robustness of these associations was evaluated by additionally controlling for PM_2.5 mass.

RESULTS

For size ranges from 0.01 to 0.3 µm, there were significant positive associations between particle number concentrations and daily emergency-room visits for stroke with the strongest associations occurring for the size range 0.05-0.1 µm. The size-dependent pattern was not changed by adjusting for PM_2.5 and gaseous pollutants. The associations of daily emergency-room visits for stroke also varied considerably by various PM_2.5 constituents. After controlling for the simultaneous exposure to PM_2.5 and gaseous pollutants in two-pollutant models, we identified 11 out of 35 constituents that had robust associations, these being organic carbon, elemental carbon, chlorine, magnesium, ammonium, nitrate, sulfate, copper, manganese, lead and zinc.

CONCLUSION

Ultra-fine particles and some PM_2.5 constituents (i.e., carbonaceous fractions, inorganic ions and some elements) may be mainly responsible for the excess risk of stroke induced by PM_2.5.

Smaller particular matter, larger risk of female lung cancer incidence? Evidence from 436 Chinese counties

BACKGROUND

Many studies have reported the effects of PM_2.5 and PM₁₀ on human health, however, it remains unclear whether particular matter with finer particle size has a greater effect.

OBJECTIVES

This work aims to examine the varying associations of the incidence rate of female lung cancer with PM₁, PM_2.5 and PM₁₀ in 436 Chinese cancer registries between 2014 and 2016.

METHODS

The effects of PM₁, PM_2.5 and PM₁₀ were estimated through three regression models, respectively. Mode l only included particular matter, while Model 2 and Model 3 further controlled for time and location factors, and socioeconomic covariates, respectively. Moreover, two sensitivity analyses were performed to investigate the robustness of three particular matte effects. Then, we examined the modifying role of urban-rural division on the effects of PM₁, PM_2.5 and PM₁₀, respectively.

RESULTS

The change in the incidence rate of female lung cancer relative to its mean was 5.98% (95% CI: 3.40, 8.56%) for PM₁, which was larger than the values of PM_2.5 and PM₁₀ at 3.75% (95% CI: 2.33, 5.17%) and 1.57% (95% CI: 0.73, 2.41%), respectively. The effects of three particular matters were not sensitive in the two sensitivity analyses. Moreover, urban-rural division positively modified the associations of the incidence rate of female lung cancer with PM₁, PM_2.5 and PM₁₀.

CONCLUSIONS

The effect on the incidence rate of female lung cancer was greater for PM₁, followed by PM_2.5 and PM₁₀. There were positive modifying roles of urban-rural division on the effects of three particular matters. The finding supports the argument that finer particular matters are more harmful to human health, and also highlights the great significance to develop guidelines for PM₁ control and prevention in Chinese setting.

Ambient particulate matter (PM1, PM2.5, PM10) and childhood pneumonia: The smaller particle, the greater short-term impact?

BACKGROUND

Smaller sizes of ambient particulate matter (PM) can be more toxic and can be breathed into lower lobes of a lung. Children are particularly vulnerable to PM air pollution because of their adverse effects on both lung functions and lung development. However, it remains unknown whether a smaller PM has a greater short-term impact on childhood pneumonia.

AIMS

We compared the short-term effects on childhood pneumonia from PM with aerodynamic diameters ≤1 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), respectively.

METHODS

Daily time-series data (2016-2018) on pneumonia hospitalizations in children aged 0-17 years, records of air pollution (PM₁, PM_2.5, PM₁₀, and gaseous pollutants), and weather conditions were obtained for Hefei, China. Effects of different PM were quantified using a quasi-Poisson generalized additive model after controlling for day of the week, holiday, seasonality and long-term time trend, and weather variables. Stratified analyses (gender, age, and season) were also performed.

RESULTS

For each 10 μg/m³ increase in PM₁, PM_2.5, and PM₁₀ concentrations over the past three days (lag 0-2), the risk of pneumonia hospitalizations increased by 10.28% (95%CI: 5.88%-14.87%), 1.21% (95%CI: 0.34%-2.09%), and 1.10% (95%CI: 0.44%-1.76%), respectively. Additionally, both boys and girls were at risk of PM₁ effects, while PM_2.5 and PM₁₀ effects were only seen in boys. Children aged ≤12 months and 1-4 years were affected by PM₁, but PM_2.5 and PM₁₀ were only associated with children aged 1-4 years. Furthermore, PM₁ effects were greater in autumn and winter, while greater PM_2.5 and PM₁₀ effects were evident only in autumn.

CONCLUSION

This study suggests a greater short-term impact on childhood pneumonia from PM₁ in comparison to PM_2.5 and PM₁₀. Given the serious PM pollution in China and other rapid developing countries due to various combustions and emissions, more investigations are needed to determine the impact of different PM on childhood respiratory health.

Association between short-term exposure to ambient nitrogen dioxide and the risk of conjunctivitis in Hefei, China: A time-series analysis

BACKGROUND

Conjunctivitis, one of the most common ocular surface diseases, can be caused by many contributors. However, the important role of air pollution has been inadequately evaluated, particularly in countries with poor air quality. This study aims to explore the possible association of short-term ambient nitrogen dioxide (NO₂) exposure with the risk of outpatient visits for conjunctivitis.

METHODS

A total of 43,462 conjunctivitis patients from January 1, 2014 to December 31, 2018 were identified from the Department of Ophthalmology of The Second Affiliated Hospital of Anhui Medical University, Hefei, China. Such data were linked to the daily mean concentration of NO₂ at ten fixed air quality monitoring stations. A distributed lag nonlinear model (DLNM) combined with a quasi-Poisson generalized linear regression model was employed to assess the association between NO₂ exposure and the risk of outpatient visits for conjunctivitis. Stratified analyses were also performed on the basis of gender, age group and season.

RESULTS

The association of NO₂ exposure with the risk of outpatient visits for conjunctivitis was statistically significant. In the single-day lags (lag 0 to lag 11) analysis, the largest effect estimates were observed at lag 0. In the moving average exposure lags (lag 0-1 to lag 0-11) analysis, the cumulative effects were stronger than the single-day lag effects. The stratified analyses suggested that the effect of NO₂ exposure was more pronounced in females and patients aged 19-65 years and in the cold season.

CONCLUSIONS

This study confirms the evidence that short-term NO₂ exposure is associated with an increased risk of conjunctivitis outpatient visits. Our research encourages individuals to avoid outdoor activities on severe air pollution days and the government is obliged to adopt more stringent environmental policies to alleviate the effects of air pollution on human health, particularly for individuals at risk of developing conjunctivitis.

Vulnerability and Burden of All-Cause Mortality Associated with Particulate Air Pollution during COVID-19 Pandemic: A Nationwide Observed Study in Italy

BACKGROUND

Limited evidence is available on the health effects of particulate matter (PM including PM2.5 with an aerodynamic diameter ≤ 2.5 μm; PM10, ≤ 10 μm; PM2.5-10, 2.5-10 μm) during the pandemic of COVID-19 in Italy. The aims of the study were to examine the associations between all-cause mortality and PM in the pandemic period and compare them to the normal periods (2015-2019).

METHODS

We collected daily data regarding all-cause mortality (stratified by age and gender), and PM concentrations for 107 Italian provinces from 1 January 2015 to 31 May 2020. A time-stratified case-cross design with the distributed lag non-linear model was used to examine the association between PM and all-cause mortality. We also compared the counts and fractions of death attributable to PM in two periods.

RESULTS

Italy saw an increase in daily death counts while slight decreases in PM concentrations in pandemic period. Each 10 µg/m3 increase in PM was associated with much higher increase in daily all-cause mortality during the pandemic period compared to the same months during 2015-2019 (increased mortality rate: 7.24% (95%CI: 4.84%, 9.70%) versus 1.69% (95%CI: 1.12%, 2.25%) for PM2.5; 3.45% (95%CI: 2.58%, 4.34%) versus 1.11% (95%CI: 0.79%, 1.42%) for PM10; 4.25% (95%CI: 2.99%, 5.52%) versus 1.76% (95%CI: 1.14%, 2.38%) for PM2.5-10). The counts and fractions of deaths attributable to PM were higher in 2020 for PM2.5 (attributable death counts: 20,062 versus 3927 per year in 2015-2019; attributable fractions: 10.2% versus 2.4%), PM10 (15,112 versus 3999; 7.7% versus 2.5%), and PM2.5-10 (7193 versus 2303; 3.7% versus 1.4%).

CONCLUSION

COVID-19 pandemic increased the vulnerability and excess cases of all-cause mortality associated with short-term exposure to PM2.5, PM2.5-10, and PM10 in Italy, despite a decline in air pollution level.

Early-life exposure to submicron particulate air pollution in relation to asthma development in Chinese preschool children

BACKGROUND

Emerging research suggested an association of early-life particulate air pollution exposure with development of asthma in childhood. However, the potentially differential effects of submicron particulate matter (PM; PM with aerodynamic diameter ≤1 μm [PM₁]) remain largely unknown.

OBJECTIVE

This study primarily aimed to investigate associations of childhood asthma and wheezing with in utero and first-year exposures to size-specific particles.

METHODS

We conducted a large cross-sectional survey among 5788 preschool children aged 3 to 5 years in central China. In utero and first-year exposures to ambient PM₁, PM with aerodynamic diameter less than or equal to 2.5 μm, and PM with aerodynamic diameter less than or equal to 10 μm at 1 × 1-km resolution were assessed using machine learning-based spatiotemporal models. A time-to-event analysis was performed to examine associations between residential PM exposures and childhood onset of asthma and wheezing.

RESULTS

Early-life size-specific PM exposures, particularly during pregnancy, were significantly associated with increased risk of asthma, whereas no evident PM-wheezing associations were observed. Each 10-μg/m³ increase in in utero and first-year PM₁ exposure was accordingly associated with an asthma's hazard ratio in childhood of 1.618 (95% CI, 1.159-2.258; P = .005) and 1.543 (0.822-2.896; P = .177). Subgroup analyses suggest that short breast-feeding duration may aggravate PM-associated risk of childhood asthma. Each 10-μg/m³ increase in in utero exposure to PM₁, for instance, was associated with a hazard ratio of 2.260 (1.393-3.666) among children with 0 to 5 months' breast-feeding and 1.156 (0.721-1.853) among those longer breast-fed.

CONCLUSIONS

Our study added comparative evidence for increased risk of childhood asthma in relation to early-life PM exposures, highlighting stronger associations with ambient PM₁ than with PM with aerodynamic diameter less than or equal to 2.5 μm and PM with aerodynamic diameter less than or equal to 10 μm.

Intraday effects of ambient PM1 on emergency department visits in Guangzhou, China: A case-crossover study

BACKGROUND

Short-term exposure to PM_2.5 has been widely associated with human morbidity and mortality. However, most up-to-date research was conducted at a daily timescale, neglecting the intra-day variations in both exposure and outcome. As an important fraction in PM_2.5, PM₁ has not been investigated about the very acute effects within a few hours.

METHODS

Hourly data for size-specific PMs (i.e., PM₁, PM_2.5, and PM₁₀), all-cause emergency department (ED) visits and meteorological factors were collected from Guangzhou, China, 2015-2016. A time-stratified case-crossover design with conditional logistic regression analysis was performed to evaluate the hourly association between size-specific PMs and ED visits, adjusting for hourly mean temperature and relative humidity. Subgroup analyses stratified by age, sex and season were conducted to identify potential effect modifiers.

RESULTS

A total of 292,743 cases of ED visits were included. The effects of size-specific PMs exhibited highly similar lag patterns, wherein estimated odds ratio (OR) experienced a slight rise from lag 0-3 to 4-6 h and subsequently attenuated to null along with the extension of lag periods. In comparison with PM_2.5 and PM₁₀, PM₁ induced slightly larger effects on ED visits. At lag 0-3 h, for instance, ED visits increased by 1.49% (95% confidence interval: 1.18-1.79%), 1.39% (1.12-1.66%) and 1.18% (0.97-1.40%) associated with a 10-μg/m³ rise, respectively, in PM₁, PM_2.5 and PM₁₀. We have detected a significant effect modification by season, with larger PM₁-associated OR during the cold months (1.017, 1.013 to 1.021) compared with the warm months (1.010, 1.005 to 1.015).

CONCLUSIONS

Our study provided brand-new evidence regarding the adverse impact of PM₁ exposure on human health within several hours. PM-associated effects were significantly more potent during the cold months. These findings may aid health policy-makers in establishing hourly air quality standards and optimizing the allocation of emergency medical resources.

Liaison between exposure to sub-micrometric particulate matter and allergic response in children from a petrochemical industry city

The study examines the association between exposure to sub-micrometric Particulate Matter (PM₁) and allergic response in a group of sensitive young children (age: 2-10 years) from Ploiesti city, Romania. The city is the only urban agglomeration in Europe surrounded by four oil refineries. A panel study was conducted by collecting medical information from children with respiratory illnesses and atopy (n = 135). Hot Spot Analysis revealed the areas of the city that are susceptible to high levels of PM₁. We found a close interaction between exposure to PM₁ outdoor concentrations and various physiological changes and clinical symptoms in children including triggering of allergic reactions, rhinitis, alteration of lung function, upper and lower respiratory tract symptoms, and bronchial asthma. During the 2-year study period, the incidence of hospitalizations was 40.7%. Strong correlations (p < 0.001) were observed between the PM₁ exposure and hospitalizations, and exposure and Immunoglobulin E (IgE). PM₁ exposure was also correlated with eosinophils (p < 0.05). Another positive correlation was observed between hospitalizations and IgE levels (p < 0.05). The mean results of tested indicators were as follows: wheezing (5.3, 95% CI (1.4-1.8); Coeff. of var. (CV) = 30%), IgE (382, 95% CI (349-445); CV = 102%), and EO% (5.3, 95% CI (3.3-4.2); CV = 69.5%). We can conclude that exposure to PM₁ influenced the frequency of wheezing episodes, increased hospitalizations, and the levels of allergic blood indicators in children, especially in infants and pre-schoolers. CAPSULE: Exposure to sub-micrometric particles (PM₁) influences the frequency of wheezing episodes, hospitalizations, and the levels of allergic blood indicators in children, especially in infants and pre-schoolers.

Acute effects of ambient air pollution on hospital outpatients with chronic pharyngitis in Xinxiang, China

We present results on a time-series study that analyzed the acute effects of six criteria air pollutants on hospital outpatient with chronic pharyngitis (CP) in Xinxiang, China. Data on the concentration of air pollutants and CP outpatient records were collected daily in Xinxiang, China, from January 1, 2015 to December 31, 2018. This study identified 62,823 outpatients with CP. The annual average concentrations of PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃ are 75.7, 132.1, 33.2, 48.4, 1377, and 59.4 μg/m³, respectively. Further, a 10 μg/m³ increment in the concentration of PM₁₀, SO₂, NO₂, and CO corresponds to an increase of 0.28% (95% confidence interval (CI): 0.03-0.53%), 1.10% (95% CI: 0.09-2.11%), 1.82% (95% CI: 0.84-2.80%), and 0.03% (95% CI: 0.01-0.06%) in daily CP hospital outpatients, respectively. Furthermore, results indicated that outpatients under the age of 15 are more susceptible to the air pollutants, excluding O₃. Meanwhile, males might be more susceptible, and effect estimates appear slightly stronger in the cool season. Therefore, we should implement effective measures to manage air pollutants and reinforce protection of the high-risk population.