Short term effects of air pollution on health: a European approach using epidemiologic time series data: the APHEA protocol

Time series analysis in environmental epidemiology: challenges and considerations

In environmental epidemiology, time series analyses represent a widely used statistical tool. However, though being commonly used, there is soften confusion regarding the specific requirements, such as which link function might be most appropriate, when or how to control for seasonality or how to account for lags. The present overview draws from experiences in other disciplines and discusses the proper execution of time series analyses based on considerations that are relevant in environmental epidemiology. Time series analysis in environmental epidemiology focuses on acute events caused by short-term changes in exposure. These exposures should be fairly wide-spread affecting a large number of persons, usually all inhabitants of a political entity. Pollutants in air or drinking water as well as meteorological factors serve as typical examples. Despite the many time series analyses performed world-wide, some health effects that would lend themselves to that approach are still under-explored. This would include also some neurological and psychiatric endpoints. Int J Occup Med Environ Health. 2023;36(6):704-16.

The role of gene-ambient air pollution interactions in paediatric asthma

Globally, asthma prevention and treatment remain a challenge. Ambient air pollution (AAP) is an environmental risk factor of special interest in asthma research. AAP is poorly defined and has been subdivided either by the origin of the air pollution or by the specific bioactive compounds. The link between AAP exposure and asthma exacerbations is well established and has been extensively reviewed. In this narrative review, we discuss the specific genetic variants that have been associated with increased AAP sensitivity and impact in paediatric asthma. We highlight the relative importance of variants associated with genes with a role in oxidant defences and the nuclear factor-κB pathway supporting a potential central role for these pathways in AAP sensitivity.

A mixed-methods evaluation of the one-way door and CitySafe patrol policies in Whangarei, New Zealand

In this paper, we evaluate the impacts of one-way door and CitySafe patrol policies in Whangarei, New Zealand, using a mixed-methods approach. In the quantitative analyses, we apply interrupted time series analysis and difference-in-differences analysis to data on antisocial behaviour derived from CCTV footage, and to police calls-for-service data. In the qualitative analysis, we apply thematic analysis to data from semi-structured interviews with 33 local stakeholders. We find a statistically significant increase in observed antisocial behaviour, but statistically significant decreases in violence and drug and alcohol offences, except when other small cities are used as a control group. In the qualitative analysis, a large majority of interviewees thought that the policy had reduced alcohol-related harm and increased safety, although a number of possible unintended consequences were also noted, including a reallocation of police resources, a redistribution of night-time drinking towards the suburbs, and a change in the demand for taxi companies. Overall, there is evidence only that the policies have reduced perceived alcohol-related harm, rather than reducing measures of harm.

InterCriteria Analysis Applied on Air Pollution Influence on Morbidity

Human health is reflected in all spheres of life and the economy. One of the main causes of morbidity and early mortality is polluted air. Ambient air pollution is a serious source of disease and mortality across the world. Cities are notorious for their high levels of air pollution and sickness. However, the precise degree of the health impacts of air pollution at the municipal level are still largely unclear. One of the main reasons for increased morbidity is the presence of particulate matter. The aim of our study is to show the relationship between elevated levels of particulate matter in the air and certain diseases. In this paper, we apply InterCriteria Analysis (ICrA) to find the correlation between the level of air pollution and the number of people seeking medical help. This is a new approach for the problem. The results show the affect of air pollution on certain diseases with a short exposure on polluted air and when the exposure is prolonged. We observed that some diseases are exacerbated by brief exposure to polluted air, while in others, exacerbation occurs after prolonged exposure.

Ambient Particulate Air Pollution and Daily Hospital Admissions in 31 Cities in Poland

A strong and consistent association has been observed between morbidity or mortality rates and PM concentration, and is well documented in many countries. In Poland, despite poor air quality, studies concerning the evaluation of acute health effects of ambient air pollution on morbidity from respiratory or cardiovascular diseases are rare. We examined the short-term impact of PMx concentration on hospital admission in 31 Polish cities based on the daily PM10, PM2.5 concentration, meteorological variables, and hospital data. The generalized additive model (GAM) and a random-effects meta-analysis were used to assess the impact of air pollution on morbidity within the exposed population. Almost 1.6 million cardiovascular admissions and 600 thousand respiratory disorders were analyzed. The RR values for PM10-related cardiovascular and respiratory hospital admissions in Poland are equal to 1.0077 (95% confidence interval, 1.0062 to 1.0092) and 1.0218 (95% confidence interval, 1.0182 to 1.0253), respectively, while for PM2.5 1.0088 (95% confidence interval, 1.0072 to 1.0103) and 1.0289 (95% confidence interval, 1.0244 to 1.0335), respectively. Moreover, a moderate heterogeneity of RR estimates was observed between the analyzed cities (I2 values from 27% to 45%). The presented analysis confirms the significant association between hospital admission and PMx concentration, especially during heating seasons.

Ambient sulfur dioxide and hospital expenditures and length of hospital stay for respiratory diseases: A multicity study in China

BACKGROUND

Ambient sulfur dioxide (SO2) has been associated with morbidity and mortality of respiratory diseases, however, its effect on length of hospital stays (LOS) and cost for these diagnoses remain unclear.

METHODS

We collected hospital admission information for respiratory diseases from all 11 cities in the Shanxi Province of China during 2017-2019. We assessed individual-level exposure by using an inverse distance weighting approach based on geocoded residential addresses. A generalized additive model was built to delineate city-specific effects of SO2 on hospitalization, hospital expenditure, and length of hospital stay for respiratory diseases. The overall effects were obtained by random-effects meta-analysis. We further estimated the respiratory burden attributable to SO2 by comparing different reference concentrations.

RESULTS

We observed significant effects of SO2 exposure on respiratory diseases. At the provincial level, each 10 μg/m3 increase in SO2 on lag03 was associated with a 0.63% (95% CI: 0.14-0.11) increase in hospital admission, an increase of 4.56 days (95% CI: 1.16-7.95) of hospital stay, and 3647.97 renminbi (RMB, Chinese money) (95% CI: 1091.05-6204.90) in hospital cost. We estimated about 6.13 (95% CI: 1.33-11.10) thousand hospital admissions, 65.77 million RMB (95% CI: 19.67-111.87) in hospital expenditure, and 82.13 (95% CI: 20.87-143.40) thousand days of hospital stay could have potentially been avoided had the daily SO2 concentrations been reduced to WHO's reference concentration (40 µg/m3). Variable values in correspondence with this reference concentration could reduce the hospital cost and LOS of each case by 52.67 RMB (95% CI: 15.75-89.59) and 0.07 days (95% CI: 0.02-0.117).

CONCLUSION

This study provides evidence that short-term ambient SO2 exposure is an important risk factor of respiratory diseases, indicating that continually tightening policies to reduce SO2 levels could effectively reduce respiratory disease burden in Shanxi Province.

Examining the immediate effects of COVID-19 on residential and commercial burglaries in Michigan: An interrupted time-series analysis

PURPOSE

Research assessing the relationship between COVID-19 lockdown restrictions and crime is growing. Attention to the nuances of burglary and intra-state variation in lockdown restrictions has received less attention. The current study contributes to this ongoing body of research by investigating the relationship between COVID-19 lockdown restrictions and burglary across four cities in Michigan.

METHOD

We use an interrupted time-series design to analyze weekly counts of residential and non-residential burglary from 2018 to 2020 in four Michigan cities: Detroit, Grand Rapids, Kalamazoo, and Lansing.

RESULTS

Findings demonstrate that the relationship between the lockdown and weekly counts of burglary vary by the type of burglary and the city being analyzed. Residential burglaries in half of the sampled cities declined during the Michigan lockdown order. Commercial burglaries increased during the lockdown order in only one of the four cities examined.

CONCLUSIONS

City-wide crime trends following lockdown orders during the pandemic are not shared equally and vary according to the type of burglary under examination. In studying the effects of COVID-19 on crime, researchers should account for crime- and city-specific dynamics which may influence crime trends. Further, practitioners and policymakers should consider the impact of similar lockdown orders on burglary trends during public health emergencies.

Short-term effects of air pollution on daily asthma-related emergency department visits in an industrial city

BACKGROUND

Epidemiological studies from Europe and North America have provided evidence that exposure to air pollution can aggravate symptoms in asthmatic patients.

METHODS

Daily number of AEDv, air pollution levels (PM10, PM2.5, SO2, NO2 and CO) and meteorological variables was obtained from Jubail Industrial City, Saudi Arabia, for the period of 2007-11. Data were analyzed using a time-series approach. Relative risks (RRs) were estimated using Poisson regression.

RESULTS

The associations between AEDv and PM10, PM2.5, SO2 and NO2 remained positive and statistically significant after mutual adjustment in the multi-pollutant model.The RR of AEDv increased by 5.4, 4.4, 3.4 and 2.2% per an inter-quartile range increase in SO2 (2.0 ppb), PM2.5 (36 μg/m3), NO2 (7.6 ppb) and PM10 (140 μg/m3), respectively. No significant associations between AEDv and CO were found.

CONCLUSIONS

Current levels of ambient air pollution are associated with AEDv in this industrial setting in the Middle East. Greater awareness of environmental health protection and the implementation of effective measures to improve the quality of air in such settings would be beneficial to public health.

Ambient PM2.5 exposure and hospital cost and length of hospital stay for respiratory diseases in 11 cities in Shanxi Province, China

BACKGROUND

Few studies have examined the effects of ambient particulate matter with an aerodynamic diameter less than or equal to 2.5 μm (PM2.5) on hospital cost and length of hospital stay for respiratory diseases in China.

METHODS

We estimated ambient air pollution exposure for respiratory cases through inverse distance-weighted averages of air monitoring stations based on their residential address and averaged at the city level. We used generalised additive models to quantify city-specific associations in 11 cities in Shanxi and a meta-analysis to estimate the overall effects. We further estimated respiratory burden attributable to PM2.5 using the standards of WHO (25 µg/m3) and China (75 µg/m3) as reference.

RESULTS

Each 10 µg/m3 increase in lag03 PM2.5 corresponded to 0.53% (95% CI: 0.33% to 0.73%) increase in respiratory hospitalisation, an increment of 3.75 thousand RMB (95% CI: 1.84 to 5.670) in hospital cost and 4.13 days (95% CI: 2.51 to 5.75) in length of hospital stay. About 9.7 thousand respiratory hospitalisations, 132 million RMB in hospital cost and 145 thousand days of hospital stay could be attributable to PM2.5 exposures using WHO's guideline as reference. We estimated that 193 RMB (95% CI: 95 to 292) in hospital cost and 0.21 days (95% CI: 0.13 to 0.30) in hospital stay could be potentially avoidable for an average respiratory case.

CONCLUSION

Significant respiratory burden could be attributable to PM2.5 exposures in Shanxi Province, China. The results need to be factored into impact assessment of air pollution policies to provide a more complete indication of the burden addressed by the policies.

How do ultrafine particles in urban air affect ambulatory blood pressure?

INTRODUCTION

Air in urban areas is usually contaminated with particle matter. High concentrations lead to a rise in the risk of cardiovascular and respiratory diseases. Some studies have reported that ultrafine particles (UFP) play a greater role in cardiovascular diseases than other particle matter, particularly regarding hypertensive crises and DBP, although in the latter such effects were described concerning clinical blood pressure (BP). In this study, we evaluate the relationship between 24-h ambulatory BP monitoring (ABPM) and atmospheric UFP concentrations in Barcelona.

METHODS

An observational study of individual patients' temporal and geographical characteristics attended in Primary Care Centres and Hypertensive Units during 2009-2014 was performed.

RESULTS

The participants were 521 hypertensive patients, mean age 56.8 years (SD 14.5), 52.4% were women. Mean BMI was 28.0 kg/m and the most prominent cardiovascular risk factors were diabetes (N = 66, 12.7%) and smoking (N = 79, 15.2%). We describe UFP effects at short-term and up to 1 week (from lag 0 to 7). For every 10 000 particle/cm UFP increase measured at an urban background site, a corresponding statistically significant increase of 2.7 mmHg [95% confidence interval = (0.5-4.8)] in 24-h DBP with ABPM for the following day was observed (lag 1).

CONCLUSION

We have observed that a rise in UFP concentrations during the day prior to ABPM is significantly associated with an increase in 24 h and diurnal DBP. It has been increasingly demonstrated that UFP play a key role in cardiovascular risk factors and, as we have demonstrated, in good BP control.

Does climatic zone of birth modify the temperature-mortality association of London inhabitants during the warm season? A time-series analysis for 2004-2013

BACKGROUND

It is known that on days with high temperatures higher mortality is observed and there is a minimum mortality temperature (MMT) point which is higher in places with warmer climate. This indicates some population adaptation to local climate but information on how quickly this adaptation will occur under climate change is lacking.

METHODS

To investigate this, we associated daily mortality data with temperature during the warm period in 2004-2013 for London inhabitants born in five climatic zones (UK, Tropical, Sub-tropical, Boreal and Mixed). We fitted Poisson regression with distributed-lag non-linear models for each climatic zone group separately to estimate group-specific exposure-response associations and MMTs. We report relative risks of death comparing the 95th percentile (21 °C) and maximum (25 °C) of the temperature distribution in London with the zone-specific minimum mortality temperature.

RESULTS

No heat-related mortality was observed for people born in countries with Sub-tropical and Mixed climates. We observed an increase of 26%, 35% and 39% in the risk of death at 25 °C compared to the MMT in people born in the UK (marine climate), Tropical and Boreal climate respectively. The temperatures with the lowest mortality in these groups ranged from 15.9 to 17.7 °C.

DISCUSSION

Our findings imply that people born in different climatic zones do not adapt fully to their new environment within their lifetime. This implies that populations may not adapt readily to climate change and will suffer increased effects from heat. In the presence of climate change, policy makers should be aware of a delayed process of adaptation.

Public Health Considerations for PM10 in a High-Pollution Megacity: Influences of Atmospheric Condition and Land Coverage

This paper analyzes the PM10 concentrations and influences of atmospheric condition (AC) and land coverage (LC) on a high-pollution megacity (Bogota, Colombia) from a public health viewpoint. Information of monitoring stations equipped with measuring devices for PM10/temperature/solar-radiation/wind-speed were used. The research period lasted eight years (2007–2014). AC and LC were determined after comparing daily PM10 concentrations (DPM10) to reference limits published by the World Health Organization (WHO). ARIMA models for DPM10 were also developed. The results indicated that urban sectors with lower atmospheric instability (AI) had a 2.85% increase in daily mortality (DM) in relation to sectors with greater AI. In these sectors of lower AI, impervious LC predominated, instead of vegetated LC. An ARIMA analysis revealed that a greater extent of impervious LC around a station led to a greater effect on previous days’ DPM10 concentrations. Extreme PM10 episodes persisted for up to two days. Extreme pollution episodes were probably also preceded by low mixing-layer heights (between 722–1085 m). The findings showed a 13.0% increase in WHO standard excesses (PE) for each 10 µg/m3 increase in DPM10, and a 0.313% increase in DM for each 10% increase in PE. The observed average reduction of 14.8% in DPM10 (−0.79% in DM) was probably due to 40% restriction of the traffic at peak hours.

Review: Strategies for using satellite-based products in modeling PM2.5 and short-term pollution episodes

Short-term air pollution episodes motivate improved understanding of the association between air pollution and acute morbidity and mortality episodes, and triggers required mitigation plans. A variety of methods have been employed to estimate exposure to air pollution episodes, including GIS-based dispersion models, interpolation between sparse monitoring sites, land-use regression models, optimization models, line- or area-dispersion plume models, and models using information from imaging satellites, often including land-use and meteorological variables. There has been increasing use of satellite-borne aerosol products for assessing short-term air quality events. They provide better spatial coverage, but currently at the price of low temporal coverage and rather crude spatial resolution. This is a brief review on using satellite data for modeling short-term air quality and pollution events. The review can be pursued as a practical guide for modeling air quality with satellite-based products, as it includes important questions that should be considered in both the study design as well as the model development stages. Progress in this field is detailed and includes published models and their use in environmental and health studies. Both current and future satellite-borne capabilities are covered. It also provides links to access and download relevant datasets and some example R code for data processing and modeling.

Impact of Relative Change in Temperature and Atmospheric Pressure on Acute Aortic Syndrome Occurrence in France

Acute aortic syndromes (AAS) have been related to significant circadian and seasonal conditions. We used time series analyses to study the impact of meteorological variations on AAS occurrence. We retrospectively assessed 140 patients presenting with AAS over a 6-year period in a French university hospital. Average daily temperature (T) and atmospheric pressure (AP) at the location of the event were collected within the previous 10 days, and their association with AAS investigated with generalized additive models. A decrease in temperature of more than 5 °C within the previous seven days was significantly associated with an increased risk of AAS occurrence (OR equal to 1.86 [1.06; 3.44]). Subgroup analysis revealed that the risk was only significant among normotensive individuals (n = 41) free from blood pressure lowering medication (OR equal to 2.3 [1.05; 5.37]), but not among hypertensive individuals under blood pressure lowering medication despite a larger patient number (n = 99). Similarly, only among the subgroup of normotensive individuals a decrease of AP between 2 and 4 kPa within the previous 3 days was associated with an increased risk of AAS (OR equal to 2.93 [1.1; 8.15]) and an increased between 2 and 4 kPa was associated with a decreased risk (OR equal to 0.59 [0.36; 1.00]). Variations of meteorological conditions (temperature and AP) within the previous week seem to have effects on triggering AAS especially among the population free from blood pressure lowering medication.

Space-time analysis of the effect of air pollution on children's health

The study aimed to investigate the short-term association between air pollution and emergency treatments for respiratory diseases in children 0 to 6 years of age. This was an ecological space-time study in Greater Metropolitan Vitória, Espírito Santo State, Brazil. A Poisson regression general additive model (GAM) used the number of daily treatments for respiratory diseases as the dependent variable, and the independent variables were daily concentrations of air pollutants (PM10, SO2, NO2, O3, and CO), temperature, humidity, and precipitation. Average daily concentrations were used to make estimates for the entire metropolitan area and in loco analyses considering children residing in a 2km radius around 8 air quality monitoring stations. An increase of 10μg/m3 in the concentration of air pollutants increased the risk of emergency treatment for respiratory disease. In the overall area, for PM10, the increase was 2.43%, 2.73%, and 3.29% in the cumulative values at 5, 6, and 7 days, respectively. For SO2, the increase was 4.47% on the day of exposure, 5.26% two days later, and 6.47%, 8.8%, 8.76%, and 7.09% for the cumulative values at days 2, 3, 4, and 5 days, respectively. CO showed a significant association for residents around two stations, and O3 for only one. Even within the limits set by the World Health Organization, the pollutants PM10, SO2, NO2, and O3 are associated with increased risk of treatment for respiratory diseases in children 0 to 6 years of age, and some effects were only identified when disaggregating by neighborhood, i.e., in loco, which allows capturing greater variation in the data.

[Chronic obstructive pulmonary disease and cardiovascular comorbidity]

In recent years, a greater understanding of the heterogeneity and complexity of chronic obstructive pulmonary disease (COPD) has come from the point of view of an integrated clinical assessment of severity, pathophysiology, and the relationship with other pathologies. A typical COPD patient suffers on average 4 or more concomitant diseases and every day about a third of patients take from 5 to 10 different drugs. The mechanisms of the interaction of COPD and cardiovascular disease (CVD) include the effects of systemic inflammation, hyperinflation (hyperinflation) of the lungs and bronchial obstruction. The risk of developing CVD in patients with COPD is on average 2-3 times higher than in people of a comparable age in the general population, even taking into account the risk of smoking. The prevalence of coronary heart disease, heart failure, and rhythm disturbances among COPD patients is significantly higher than in the general population. The article discusses in detail the safety of prescribing various groups of drugs for the treatment of CVD in patients with COPD. Achieving success in understanding and managing patients with COPD and CVD is possible using an integrated multidisciplinary approach.

A Review of Early Injection Strategy in Premixed Combustion Engines

Due to the increasing awareness of environmental protection, limitations on exhaust emissions of diesel engines have become increasingly stringent. This challenges diesel engine manufacturers to find a new balance between engine performance and emissions. Advanced combustion modes for diesel engines, such as homogeneous charge compression ignition (HCCI) and premixed charge compression ignition (PCCI), which can simultaneously reduce exhaust emissions and substantially improve thermal efficiency, have drawn increasing attention. In order to allow enough time to prepare the homogeneous mixture, the early injection strategy has been utilized widely in HCCI and PCCI diesel engines. This paper is aimed at providing a comprehensive review of the effects of early injection parameters on the performance and emissions of HCCI and PCCI engines fueled by both diesel and alternative fuels. Various early injection parameters, including injection pressure, injection timing, and injection angle, are discussed. In addition, the effect of the blending ratio of alternative fuels is also summarized. Every change in parameters has its own advantages and disadvantages, which are explained in detail in order to help researchers choose the best early injection parameters for HCCI and PCCI engines.

Acute Exposure to SiO2 Nanoparticles Affects Protein Synthesis in Bergmann Glia Cells

Attractive due to an alleged high biocompatibility, silica nanoparticles have been widely used in the field of nanomedicine; however, their proven capacity to induce the synthesis and release of pro-inflammatory cytokines in several cellular models has raised concern about their safety. Glutamate, the main excitatory amino acid transmitter triggers a wide variety of signal transduction cascades that regulate protein synthesis at transcriptional and translational levels. A stimulus-dependent dynamic change in the protein repertoire in neurons and glia cells is the molecular framework of higher brain functions. Within the cerebellum, Bergmann glia cells are the most abundant non-neuronal cells and span the entire molecular layer of the cerebellar cortex, wrapping the synapses in this structure. Taking into consideration the functional role of Bergmann glia in terms of the recycling of glutamate, lactate supply to neurons, and prevention of neurotoxic insults, we decided to investigate the possibility that silica nanoparticles affect Bergmann glia and by these means alter the major excitatory neurotransmitter system in the brain. To this end, we exposed cultured chick cerebellar Bergmann glia cells to silica nanoparticles and measured [³⁵S]-methionine incorporation into newly synthesized polypeptides. Our results demonstrate that exposure of the cultured cells to silica nanoparticles exerts a time- and dose-dependent modulation of protein synthesis. Furthermore, altered patterns of eukaryotic initiation factor 2 alpha and eukaryotic elongation factor 2 phosphorylation were present upon nanoparticle exposure. These results demonstrate that glia cells respond to the presence of this nanomaterial modifying their proteome, presumably in an effort to overcome any plausible neurotoxic effect.

Advancing our Understanding of Heat Wave Criteria and Associated Health Impacts to Improve Heat Wave Alerts in Developing Country Settings

Health effects of heat waves with high baseline temperatures in areas such as India remain a critical research gap. In these regions, extreme temperatures may affect the underlying population’s adaptive capacity; heat wave alerts should be optimized to avoid continuous high alert status and enhance constrained resources, especially under a changing climate. Data from registrars and meteorological departments were collected for four communities in Northwestern India. Propensity Score Matching (PSM) was used to obtain the relative risk of mortality and number of attributable deaths (i.e., absolute risk which incorporates the number of heat wave days) under a variety of heat wave definitions (n = 13) incorporating duration and intensity. Heat waves’ timing in season was also assessed for potential effect modification. Relative risk of heat waves (risk of mortality comparing heat wave days to matched non-heat wave days) varied by heat wave definition and ranged from 1.28 [95% Confidence Interval: 1.11–1.46] in Churu (utilizing the 95th percentile of temperature for at least two consecutive days) to 1.03 [95% CI: 0.87–1.23] in Idar and Himmatnagar (utilizing the 95th percentile of temperature for at least four consecutive days). The data trended towards a higher risk for heat waves later in the season. Some heat wave definitions displayed similar attributable mortalities despite differences in the number of identified heat wave days. These findings provide opportunities to assess the “efficiency” (or number of days versus potential attributable health impacts) associated with alternative heat wave definitions. Findings on both effect modification and trade-offs between number of days identified as “heat wave” versus health effects provide tools for policy makers to determine the most important criteria for defining thresholds to trigger heat wave alerts.

Impact of air pollution on hospital admissions with a focus on respiratory diseases: a time-series multi-city analysis

Together with the growing availability of data from electronic records from healthcare providers and healthcare systems, an assessment of associations between different environmental parameters (e.g., pollution levels and meteorological data) and hospitalizations, morbidity, and mortality has become possible. This study aimed to assess the association of air pollution and hospitalizations using a large database comprising almost all hospitalizations in Poland. This time-series analysis has been conducted in five cities in Poland (Warsaw, Białystok, Bielsko-Biała, Kraków, Gdańsk) over a period of almost 4 years (2014-2017, 1255 days), covering more than 20 million of hospitalizations. The hospitalizations have been extracted from the National Health Fund registries as daily summaries. Correlation analysis and distributed lag nonlinear models have been used to investigate for statistically relevant associations of air pollutants on hospitalizations, trying by various methods to minimize potential bias from atmospheric parameters, days of the week, bank holidays, etc. A statistically significant increase of respiratory disease hospitalizations has been detected after peaks of particulate matter concentrations (particularly PM_2.5, between 0.9 and 4.5% increase per 10 units of pollutant increase, and PM₁₀, between 0.9 and 3.5% per 10 units of pollutant increase), with a typical time lag between the pollutant peak and the event of 2 to 6 days. For other pollution parameters and other types of hospitalizations (e.g., cardiovascular events, eye and skin diseases, etc.), a weaker and ununiform correlations were recorded. Ambient air pollution exposure increases are associated with a short-term increase of hospitalizations due to respiratory tract diseases. The most prominent effect was recorded with the correlation of PM_2.5 and PM₁₀. There is only weak evidence indicating that such short-term associations exist between peaks of air pollution concentrations and increased hospitalizations for other (e.g., cardiovascular) diseases. The obtained information could be used to better predict hospitalization patterns and costs for the healthcare system and perhaps trigger additional vigilance on particulate matter pollution in the cities.

Variation in Cold-Related Mortality in England Since the Introduction of the Cold Weather Plan: Which Areas Have the Greatest Unmet Needs?

: The Cold Weather Plan (CWP) in England was introduced to prevent the adverse health effects of cold weather; however, its impact is currently unknown. This study characterizes cold-related mortality and fuel poverty at STP (Sustainability and Transformation Partnership) level, and assesses changes in cold risk since the introduction of the CWP. Time series regression was used to estimate mortality risk for up to 28 days following exposure. Area level fuel poverty was used to indicate mitigation against cold exposure and mapped alongside area level risk. We found STP variations in mortality risk, ranging from 1.74, 1.44⁻2.09 (relative risk (RR), 95% CI) in Somerset, to 1.19, 1.01⁻1.40 in Cambridge and Peterborough. Following the introduction of the CWP, national-level mortality risk declined significantly in those aged 0⁻64 (1.34, 1.23⁻1.45, to 1.09, 1.00⁻1.19), but increased significantly among those aged 75+ (1.36, 1.28⁻1.44, to 1.58, 1.47⁻1.70) and for respiratory conditions (1.78, 1.56⁻2.02, to 2.4, 2.10⁻2.79). We show how spatial variation in cold mortality risk has increased since the introduction of the CWP, which may reflect differences in implementation of the plan. Combining risk with fuel poverty information identifies 14 STPs with the greatest need to address the cold effect, and that would gain most from enhanced CWP activity or additional intervention measures.

PM2.5 levels strongly associate with multiple sclerosis prevalence in the Province of Padua, Veneto Region, North-East Italy

Background:

Incidence and prevalence trends of multiple sclerosis (MS) in the Province of Padua, North-East Italy, suggest that environmental factors may be associated with increased MS risk.

Objective:

To investigate the association of PM2.5 with MS prevalence in one of the most polluted geographical area of Italy.

Methods:

In total, 1435 Italian MS patients residing in the Province of Padua were enrolled. The province surface was classified into urban areas, isolated villages, industrialized places, and countryside. Satellite-derived dust-free and sea salt-free PM2.5 concentrations (annual average 1998–2015, μg/m3) allowed the identification of 18 classes of territorial sections with statistically evaluable numbers of inhabitants. Possible correlations between residential locality types, PM2.5 concentrations, and MS prevalence were investigated.

Results:

MS prevalence was significantly ( p < 0.0001) higher in urban areas (ranging from 219 in Padua City to 169/100,000 in other urban areas) compared to isolated villages (116/100,000) or rural domains (109/100,000) and strongly correlated with the annual average concentration of PM2.5 ( r = 0.81, p < 0.001). Regression analysis further associated MS cases with PM.2.5 average concentration ( β = 0.11, p < 0.001).

Conclusion:

In the Province of Padua, MS prevalence is strongly associated with PM2.5 exposure suggesting that air pollutants may be one of the possible environmental risk factors for MS.

Exposures to Atmospheric PM10 and PM10-2.5 Affect Male Semen Quality: Results of MARHCS Study

Studies have shown that the effects of ambient particulate matter (PM) may be related to particle's size. However, results on the relationships between different PM and reproductive health are controversial. To explore the impacts of various PM fractions on male reproductive health, a total of 796 eligible subjects recruited in 2013 baseline investigation. In addition, there were 656 (82.4%) and 568 (71.3%) subjects participated follow-up surveys in 2014 and 2015, respectively. We used multivariable regression analysis and mixed-effect model to investigate the associations between air pollutants PM₁₀, PM_10-2.5, and PM_2.5 exposures and semen quality, sperm DNA fragmentation and serum reproductive hormones of subjects. In the preliminary regression analysis, PM₁₀, PM_10-2.5, and PM_2.5 exposure all associated with sperm concentration, morphology, sperm high DNA stainability (HDS), serum estradiol and testosterone levels. However, in mixed models, we only found that PM₁₀ exposure were negatively associated with sperm normal morphology (95% CI: -14.13, -24.47) but positively associated with sperm progressive motility (95% CI: 23.00, 8.49), and PM_10-2.5 exposure was inversely associated with sperm concentration (95% CI: -9.06, -27.31) after multiplicity adjustment. Our results provide the evidence that air PM₁₀ and PM_10-2.5 exposures, not PM_2.5, are risk factors of semen quality.

Acute effects of fine particulate matter constituents on mortality: A systematic review and meta-regression analysis

BACKGROUND

The link between PM_2.5 exposure and adverse health outcomes is well documented from studies across the world. However, the reported effect estimates vary across studies, locations and constituents. We aimed to conduct a meta-analysis on associations between short-term exposure to PM_2.5 constituents and mortality using city-specific estimates, and explore factors that may explain some of the observed heterogeneity.

METHODS

We systematically reviewed epidemiological studies on particle constituents and mortality using PubMed and Web of Science databases up to July 2015.We included studies that examined the association between short-term exposure to PM_2.5 constituents and all-cause, cardiovascular, and respiratory mortality, in the general adult population. Each study was summarized based on pre-specified study key parameters (e.g., location, time period, population, diagnostic classification standard), and we evaluated the risk of bias using the Office of Health Assessment and Translation (OHAT) Method for each included study. We extracted city-specific mortality risk estimates for each constituent and cause of mortality. For multi-city studies, we requested the city-specific risk estimates from the authors unless reported in the article. We performed random effects meta-analyses using city-specific estimates, and examined whether the effects vary across regions and city characteristics (PM_2.5 concentration levels, air temperature, elevation, vegetation, size of elderly population, population density, and baseline mortality).

RESULTS

We found a 0.89% (95% CI: 0.68, 1.10%) increase in all-cause, a 0.80% (95% CI: 0.41, 1.20%) increase in cardiovascular, and a 1.10% (95% CI: 0.59, 1.62%) increase in respiratory mortality per 10μg/m³ increase in PM_2.5. Accounting for the downward bias induced by studies of single days, the all-cause mortality estimate increased to 1.01% (95% CI: 0.81, 1.20%). We found significant associations between mortality and several PM_2.5 constituents. The most consistent and stronger associations were observed for elemental carbon (EC) and potassium (K). For most of the constituents, we observed high variability of effect estimates across cities.

CONCLUSIONS

Our meta-analysis suggests that (a) combustion elements such as EC and K have a stronger association with mortality, (b) single lag studies underestimate effects, and (c) estimates of PM_2.5 and constituents differ across regions. Accounting for PM mass in constituent's health models may lead to more stable and comparable effect estimates across different studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO: CRD42017055765.

Short-term exposure to air pollutants increases the risk of ST elevation myocardial infarction and of infarct-related ventricular arrhythmias and mortality

BACKGROUND

The relation between STEMI and air pollution (AP) is scant. We aimed to investigate the short term association between AP and the incidence of STEMI, and STEMI-related ventricular arrhythmias (VA) and mortality.

METHODS

The study was carried out in the area of Barcelona from January 2010 to December 2011. Daily STEMI rates and incidence of STEMI-related VA and mortality were obtained prospectively. The corresponding daily levels of the main pollutants were recorded as well as the atmospheric variables. Three cohorts were defined in order to minimize exposure bias. The magnitude of association was estimated using a time-series design and was adjusted according to atmospheric variables.

RESULTS

The daily rate of hospital admissions for STEMI was associated with increases in PM 2.5, PM 10, lead and NO2 concentrations. VA incidence and mortality were associated with increases in PM 2.5 and PM 10 concentrations. In the most specific cohort, BCN (Barcelona) Attended & Resident, STEMI incidence was associated with increases in PM 2.5 (1.009% per 10μg/m³) and PM 10 concentrations (1.005% per 10μg/m³). VA was associated with increases in PM 2.5 (1.021%) and PM 10 (1.015%) and mortality was associated with increases in PM 2.5 (1.083%) and PM 10 (1.045%).

CONCLUSIONS

Short-term exposure to high levels of PM 2.5 and PM 10 is associated with increased daily STEMI admissions and STEMI-related VA and mortality. Exposure to high levels of lead and NO2 is associated with increased daily STEMI admissions, and NO2 with higher mortality in STEMI patients.

Pollen exposure and hospitalization due to asthma exacerbations: daily time series in a European city

Exposure to pollen can contribute to increased hospital admissions for asthma exacerbation. This study applied an ecological time series analysis to examine associations between atmospheric concentrations of different pollen types and the risk of hospitalization for asthma in London from 2005 to 2011. The analysis examined short-term associations between daily pollen counts and hospital admissions in the presence of seasonal and long-term patterns, and allowed for time lags between exposure and admission. Models were adjusted for temperature, precipitation, humidity, day of week, and air pollutants. Analyses revealed an association between daily counts (continuous) of grass pollen and adult hospital admissions for asthma in London, with a 4-5-day lag. When grass pollen concentrations were categorized into Met Office pollen 'alert' levels, 'very high' days (vs. 'low') were associated with increased admissions 2-5 days later, peaking at an incidence rate ratio of 1.46 (95%, CI 1.20-1.78) at 3 days. Increased admissions were also associated with 'high' versus 'low' pollen days at a 3-day lag. Results from tree pollen models were inconclusive and likely to have been affected by the shorter pollen seasons and consequent limited number of observation days with higher tree pollen concentrations. Future reductions in asthma hospitalizations may be achieved by better understanding of environmental risks, informing improved alert systems and supporting patients to take preventive measures.

Analysis of Temporal Variability in the Short-term Effects of Ambient Air Pollutants on Nonaccidental Mortality in Rome, Italy (1998-2014)

OBJECTIVES

The association between short-term air pollution exposure and daily mortality has been widely investigated, but little is known about the temporal variability of the effect estimates. We examined the temporal relationship between exposure to particulate matter (PM) (PM₁₀, PM_2.5) and gases (NO₂, SO₂, and CO) with mortality in a large metropolitan area over the last 17 y.

METHODS

Our analysis included 359,447 nonaccidental deaths among ≥35-y-old individuals in Rome, Italy, over the study period 1998–2014. We related daily concentrations to mortality counts with a time-series Poisson regression analysis adjusted for long-term trends, meteorology, and population dynamics.

RESULTS

Annual average concentrations decreased over the study period for all pollutants (e.g., from 42.9 to 26.6 μg/m³ for PM₁₀). Each pollutant was positively associated with mortality, with estimated percentage increases over the entire study period ranging from 0.19% (95% CI: 0.13, 0.26) for a 1-Mg/m³ increase in CO (0–1 d lag) to 3.03% (95% CI: 2.44, 3.63) for a 10-μg/m³ increase in NO₂ (0–5 d lag). We did not observe clear temporal patterns in year- or period-specific effect estimates for any pollutant. For example, we estimated that a 10-μg/m³ increase in PM₁₀ was associated with 1.16% (95% CI: 0.53, 1.79), 0.99% (95% CI: 0.23, 1.77), and 1.87% (95% CI: 1.00, 2.74) increases in mortality for the periods 2001–2005, 2006–2010, and 2011–2014, respectively, and corresponding estimates for a 10-μg/m³ increase in NO₂ were 4.20% (95% CI: 3.15, 5.25), 1.78% (95% CI: 0.73, 2.85), and 3.32% (95% CI: 2.03, 4.63).

CONCLUSIONS

Mean concentrations of air pollutants have decreased over the last two decades in Rome, but effect estimates for a fixed increment in each exposure were generally consistent. These findings suggest that there has been little or no change in the overall toxicity of the air pollution mixture over time. https://doi.org/10.1289/EHP19.

Association between Air Pollution and Emergency Room Visits for Atrial Fibrillation

Despite the large prevalence in the population, possible factors responsible for the induction of atrial fibrillation (AF) events in susceptible individuals remain incompletely understood. We investigated the association between air pollution levels and emergency department admissions for AF in Rome. We conducted a 14 years’ time-series study to evaluate the association between the daily levels of air pollution (particulate matter, PM₁₀ and PM_2.5, and nitrogen dioxide, NO₂) and the daily count of emergency accesses for AF (ICD-9 code: 427.31). We applied an over-dispersed conditional Poisson model to analyze the associations at different lags after controlling for time, influenza epidemics, holiday periods, temperature, and relative humidity. Additionally, we evaluated bi-pollutant models by including the other pollutant and the influence of several effect modifiers such as personal characteristics and pre-existing medical conditions. In the period of study, 79,892 individuals were admitted to the emergency departments of Rome hospitals because of AF (on average, 15.6 patients per day: min = 1, max = 36). Air pollution levels were associated with increased AF emergency visits within 24 h of exposure. Effect estimates ranged between 1.4% (0.7–2.3) for a 10 µg/m³ increase of PM₁₀ to 3% (1.4–4.7) for a 10 µg/m³ increase of PM_2.5 at lag 0–1 day. Those effects were higher in patients ≥75 years for all pollutants, male patients for PM₁₀, and female patients for NO₂. The presence of previous cardiovascular conditions, but not other effect modifiers, increase the pollution effects by 5–8% depending on the lag. This study found evidence that air pollution is associated with AF emergency visits in the short term.

Hospital-Acquired Methicillin-Resistant Staphylococcus aureus Bloodstream Infections in Québec: Impact of Guidelines

OBJECTIVE We examined the impact of methicillin-resistant Staphylococcus aureus (MRSA) guidelines in Québec adult hospitals from January 1, 2006, to March 31, 2015, by examining the incidence rate reduction (IRR) in healthcare-associated MRSA bloodstream infections (HA-MRSA), using central-line associated bloodstream infections (CLABSIs) as a comparator. METHODS In this study, we utilized a quasi-experimental design with Poisson segmented regression to model HA-MRSA and CLABSI incidence for successive 4-week surveillance segments, stratified by teaching status. We used 3 distinct periods with 2 break points (April 1, 2007, and January 3, 2010) corresponding to major MRSA guideline publications and updates. RESULTS Over the study period, HA-MRSA incidence decreased significantly in adult teaching facilities but not in nonteaching facilities. Prior to MRSA guideline publication (2006-2007), HA-MRSA incidence decrease was not significant (P=.89), while CLABSI incidence decreased by 4% per 4-week period (P=.05). After the publication of guidelines (2007-2009), HA-MRSA incidence decreased significantly by 1% (P=.04), while no significant decrease in CLABSI incidence was observed (P=.75). HA-MRSA and CLABSI decreases were both significant at 1% for 2010-2015 (P<.001 and P=.01, respectively). These decreases were gradual rather than sudden; break points were not significant. Teaching facilities drove these decreases. CONCLUSION During the study period, HA-MRSA and CLABSI rates decreased significantly. In 2007-2009, the significant decrease in HA-MRSA rates with stable CLABSI rates suggests an impact from MRSA-specific guidelines. In 2010-2015, significant and equal IRRs for HA-MRSA and CLABSI may be due to the continuing impact of MRSA guidelines, to the impact of new interventions targeting device-associated infections in general by the 2010-2015 Action Plan, or to a combination of factors. Infect Control Hosp Epidemiol 2017;38:840-847.

Heat effects of ambient apparent temperature on all-cause mortality in Cape Town, Durban and Johannesburg, South Africa: 2006-2010

Due to climate change, an increase of 3-4°C in ambient temperature is projected along the South African coast and 6-7°C inland during the next 80years. The objective of this study was to investigate the association between daily ambient apparent temperature (Tapp) and daily all-cause non-accidental mortality (hereafter mortality) in Cape Town, Durban and Johannesburg during a 5-year study period (2006-2010). Susceptibility by sex and age groups (<15years, 15-64years and ≥65years) was also investigated. The associations were investigated with the time-stratified case-crossover epidemiological design. Models were controlled for PM₁₀, public holidays and influenza epidemics. City-specific Tapp thresholds were determined using quasi-Poisson generalised additive models. The pooled estimates by sex and age groups were determined in meta-analyses. The city-specific Tapp thresholds were 18.6°C, 24.8°C and 18.7°C, respectively for Cape Town, Durban and Johannesburg. A 3.3%, 2.6% and 2.8% increase in mortality per IQR increase in Tapp (lag0-1) was observed in Cape Town, Durban and Johannesburg, respectively above the city-specific thresholds. The elderly were more at risk in Cape Town and Johannesburg. No difference in risk was observed for males and females in the three cities. In the meta-analysis an overall significant increase of 0.9% in mortality per 1°C increase in Tapp (lag0-1) was observed for all age groups combined in the three cities. For the ≥65year group a significant increase of 2.1% in mortality was observed. In conclusion, the risks for all age groups combined and the elderly are similar to those reported in studies from developed and developing countries. The results can be used in present-day early warning systems and in risk assessments to estimate the impact of increased Tapp in the country due to climate change. Future research should investigate the association between Tapp and cause-specific mortality and also morbidity.

Seasonal analysis of the short-term effects of air pollution on daily mortality in Northeast Asia

The constituents and concentrations of pollutants, individual exposures, and biologic responses to air pollution may vary by season and meteorological conditions. However, evidence regarding seasonality of the acute effects of air pollution on mortality is limited and inconsistent. Herein, we examined seasonal patterns in the short-term associations of particulate matter (PM) smaller than 10μm (PM₁₀) with daily mortality in 29 cities of three northeast Asian countries. Stratified time-series models were used to determine whether season altered the effect of PM₁₀ on mortality. This effect was first quantified within each season and at each location using a time-series model, after which city-specific estimates were pooled using a hierarchical Bayesian model. In all data sets, 3,675,348 non-accidental deaths were registered from 1993 to 2009. In Japan, a 10μg/m³ increase in PM₁₀ was significantly associated with increases in non-accidental mortality of 0.44% (95% confidence interval [CI]: 0.03%, 0.8%) in spring and 0.42% (0.02%, 0.82%) in fall. In South Korea, a 10μg/m³ increase in PM₁₀ was significantly associated with increases in non-accidental mortality of 0.51% (0.01%, 1.01%) in summer and 0.45% (0.03%, 0.87%) in fall, in cardiovascular disease mortality of 0.96% (0.29%, 1.63%) in fall, and in respiratory disease mortality of 1.57% (0.40%, 2.75%) in fall. In China, a 10μg/m³ increase in PM₁₀ was associated with increases in non-accidental mortality of 0.33% (0.01%, 0.66%) in summer and 0.41% (0.09%, 0.73%) in winter, in cardiovascular disease mortality of 0.41% (0.08%, 0.74%) in spring and 0.33% (0.02%, 0.64%) in winter, and in respiratory diseases mortality of 0.78% (0.27%, 1.30%) in winter. Our analyses suggest that the acute effect of particulate air pollution could vary seasonally and geographically.

Development of a browser application to foster research on linking climate and health datasets: Challenges and opportunities

BACKGROUND

Improved data linkages between diverse environment and health datasets have the potential to provide new insights into the health impacts of environmental exposures, including complex climate change processes. Initiatives that link and explore big data in the environment and health arenas are now being established.

OBJECTIVES

To encourage advances in this nascent field, this article documents the development of a web browser application to facilitate such future research, the challenges encountered to date, and how they were addressed.

METHODS

A 'storyboard approach' was used to aid the initial design and development of the application. The application followed a 3-tier architecture: a spatial database server for storing and querying data, server-side code for processing and running models, and client-side browser code for user interaction and for displaying data and results. The browser was validated by reproducing previously published results from a regression analysis of time-series datasets of daily mortality, air pollution and temperature in London.

RESULTS

Data visualisation and analysis options of the application are presented. The main factors that shaped the development of the browser were: accessibility, open-source software, flexibility, efficiency, user-friendliness, licensing restrictions and data confidentiality, visualisation limitations, cost-effectiveness, and sustainability.

CONCLUSIONS

Creating dedicated data and analysis resources, such as the one described here, will become an increasingly vital step in improving understanding of the complex interconnections between the environment and human health and wellbeing, whilst still ensuring appropriate confidentiality safeguards. The issues raised in this paper can inform the future development of similar tools by other researchers working in this field.

Chemical components of respirable particulate matter associated with emergency hospital admissions for type 2 diabetes mellitus in Hong Kong

BACKGROUND

Epidemiological studies have shown that short-term exposure to particulate matter (PM) mass is associated with diabetes morbidity and mortality, although inconsistencies still exist. Variation of chemical components in PM may have contributed to these inconsistencies. We hypothesize that certain components of respirable particulate matter (PM₁₀), not simply PM₁₀ mass, can exacerbate symptoms or cause acute complications for type 2 diabetes mellitus (T2DM).

METHODS

We used a Poisson time-series model to examine the association between 17 chemical components of PM₁₀ and daily emergency hospital admissions for T2DM among residents aged 65years or above from January 1998 to December 2007 in Hong Kong. We estimated excess risk (ER%) for T2DM hospitalizations per interquartile range (IQR) increment in chemical component concentrations of days at lag₀ through lag₃, and the moving average of the same-day and previous-day (lag_0-1) in single-pollutant models. To further evaluate the independent effects of chemical components on T2DM, we controlled for PM₁₀ mass, major PM₁₀ chemical components, and gaseous pollutants in two-pollutant models.

RESULTS

In the single-pollutant models, PM₁₀ components associated with T2DM admissions include: elemental carbon, organic carbon, nitrate, and nickel. The ER% estimates per IQR increment at lag_0-1 for these four components were 3.79% (1.63, 5.95), 3.74% (0.83, 6.64), 4.58% (2.17, 6.99), and 1.91% (0.43, 3.38), respectively. Risk estimates for nitrate and elemental carbon were robust to adjustment for co-pollutant concentrations.

CONCLUSIONS

Short-term exposure to some PM₁₀ chemical components such as nitrate and elemental carbon increases the risk of acute complications or exacerbation of symptoms for the T2DM patients. These findings may have potential biological and policy implications.

Short-term NO2 exposure is associated with long-chain fatty acids in prospective cohorts from Augsburg, Germany: results from an analysis of 138 metabolites and three exposures

BACKGROUND

Short-term exposure to air pollution is associated with morbidity and mortality. Metabolites are intermediaries in biochemical processes, and associations between air pollution and metabolites can yield unique mechanistic insights.

METHODS

We used independent cross-sectional samples with targeted metabolomics (138 metabolites across five metabolite classes) from three cohort studies, each a part of the Cooperative Health Research in the Region of Augsburg (KORA). The KORA cohorts are numbered (1 to 4) according to which survey they belong to, and lettered S or F according to whether the survey was a baseline or follow-up survey. KORA F4 (N = 3044) served as our discovery cohort, with KORA S4 (N = 485) serving as the primary replication cohort. KORA F4 and KORA S4 were primarily fasting cohorts. We used the non-fasting KORA F3 (N = 377) cohort to evaluate replicated associations in non-fasting individuals, and we performed a random effects meta-analysis of all three cohorts. Associations between the 0-4-day lags and the 5-day average of particulate matter (PM)_2.5, NO₂ and ozone were modelled via generalized additive models. All air pollution exposures were scaled to the interquartile range, and effect estimates presented as percent changes relative to the geometric mean of the metabolite concentration (ΔGM).

RESULTS

There were 10 discovery cohort associations, of which seven were lysophosphatidylcholines (LPCs); NO₂ was the most ubiquitous exposure (5/10). The 5-day average NO₂-LPC(28:0) association was associated at a Bonferroni corrected P-value threshold (P < 1.2x10^-4) in KORA F4 [ΔGM = 11.5%; 95% confidence interval (CI) = 6.60, 16.3], and replicated (P < 0.05) in KORA S4 (ΔGM = 21.0%; CI = 4.56, 37.5). This association was not observed in the non-fasting KORA F3 cohort (ΔGM = -5.96%; CI = -26.3, 14.3), but remained in the random effects meta-analysis (ΔGM = 10.6%; CI = 0.16, 21).

CONCLUSIONS

LPCs are associated with short-term exposure to air pollutants, in particular NO₂ Further research is needed to understand the effect of nutritional/fasting status on these associations and the causal mechanisms linking air pollution exposure and metabolite profiles.

Validity of the Emission Weighted Proximity Model in estimating air pollution exposure intensities in large geographic areas

BACKGROUND

Accurate estimates of air pollution exposure intensities are important to support environmental epidemiology analyses that require data covering large geographic areas over multiple years. The Emission Weighted Proximity Model (EWPM) and the National-Scale Air Toxics Assessment (NATA) are two viable approaches for obtaining estimate exposure intensities. The advantages of the EWPM include its simplicity and significantly lower costs of implementation. However, very limited data are available regarding the validity of the results from the EWPM and how these results would fare when compared with those from the NATA.

METHODS

This study evaluates the validity of the estimated exposure intensities from the EWPM through a correlation analysis with ground monitoring data obtained by the Texas Commission on Environmental Quality (TCEQ). The monitoring data used in the comparison included 27 non-criteria air pollutants at 48 monitoring sites in Texas in 2005. In addition, this study compares the results from the EWPM with those from NATA using the TCEQ data as a gold standard.

RESULTS

Analysis results suggest that estimated exposure intensities from the EWPM and the NATA were comparable when the intensities from both approaches are used to categorize environmental exposure intensities into different levels in relative terms.

CONCLUSION

These findings suggest that the EWPM is a valid alternative approach to the NATA in situations where epidemiological analysis requires both environmental data and health outcome data that cover a large geographic area over multiple years.

Assessment of resident's exposure level and health economic costs of PM10 in Beijing from 2008 to 2012

Epidemiological studies have asserted a negative association between atmospheric particulates and human health, especially particulate matter (PM10), which can cause a noticeable damage to human health. In recent years, PM10 has become the primary pollutant in major cities in China. It is crucial to evaluate the health impacts of PM10 to make pollution control policies and protect public health. For health-based assessments, human exposure evaluation is a key step, which is related to offering an exact exposure date for assessment. Using high-density PM10 and population data based on the Geographic Information System (GIS), this study estimated the impact of PM10 on human exposure levels and combined the exposure-response function with the health-economic loss relationship to assess the effect of PM10 on human health in Beijing from 2008 to 2012 quantitatively. The results showed that the population distribution was highly centralized in urban areas, especially inside the fifth ring road. A high proportion, 63.4% of the population, was exposed to the range of 120 to 130μg/m(3). Approximately 44.1% of that population was located inside the fifth ring road, and approximately 55.9% of it was located outside of the fifth ring road. The spatial distribution of the economic cost associated with PM10 from 2008 to 2012 was uneven, being highly centralized in urban areas, especially inside the fifth ring road, similar to the population densities. The economic cost increased from 2008 to 2012, similar to GDP. The proportion of economic cost to Beijing's GDP decreased from 2008 to 2012. The average economic cost of 5years inside the fifth ring road was 4.55billion US$; that of the outside was 4.95billion US$. The proportions of average economic losses compared with GDP inside and outside of the fifth ring road changed slightly in the period from 2008 to 2012.

Exacerbations of Chronic Obstructive Pulmonary Disease (COPD): An Ecological Study in the Basque Country, Spain (2000-2011)

Chronic obstructive pulmonary disease (COPD) is a prevalent condition in adults aged ≥40 years characterized by progressive airflow limitation associated with chronic inflammatory response to noxious particles in the airways and lungs. Smoking, genetics, air pollution, nutrition and other factors may influence COPD development. Most hospitalizations and deaths for COPD are caused by its acute exacerbations, which greatly affect the health and quality of life of COPD patients and pose a high burden on health services. The aims of this project were to identify trends, geographic patterns and risk factors for COPD exacerbations, as revealed by hospitalizations and deaths, in the Basque Country, Spain, over a period of 12 years (2000-2011). Hospitalization and mortality rates for COPD were 262 and 18 per 100,000 population, respectively, with clusters around the biggest cities. Hospital mortality was 7.4%. Most hospitalized patients were male (77.4%) and accounted for 72.1% of hospital mortality. Hospitalizations decreased during the study period, except for 50-64 year-old women, peaking significantly. Using a multivariate modeling approach it was shown that hospitalizations were positively correlated with increased atmospheric concentrations of NO₂, CO, PM₁₀, and SO₂, and increased influenza incidence, but were negatively associated with increased temperatures and atmospheric O₃ concentration. COPD exacerbations decreased in the Basque Country during 2000-2011, but not among 50-64-year-old women, reflecting the high smoking prevalence among Spanish women during the 1970-1990s. The main metropolitan areas were those with the highest risk for COPD exacerbations, calling attention to the role of heavy car traffic. Influenza virus, cold temperatures, and increased atmospheric NO₂, CO, PM₁₀, and SO₂ (but decreased O₃) concentrations were identified as potential contributors to the burden of COPD exacerbations in the community. These findings are important for both the understanding of the disease process and in providing potential targets for COPD-reducing initiatives and new avenues for research.

Associations between ultrafine and fine particles and mortality in five central European cities - Results from the UFIREG study

BACKGROUND

Evidence on health effects of ultrafine particles (UFP) is still limited as they are usually not monitored routinely. The few epidemiological studies on UFP and (cause-specific) mortality so far have reported inconsistent results.

OBJECTIVES

The main objective of the UFIREG project was to investigate the short-term associations between UFP and fine particulate matter (PM)<2.5μm (PM2.5) and daily (cause-specific) mortality in five European Cities. We also examined the effects of PM<10μm (PM10) and coarse particles (PM2.5-10).

METHODS

UFP (20-100nm), PM and meteorological data were measured in Dresden and Augsburg (Germany), Prague (Czech Republic), Ljubljana (Slovenia) and Chernivtsi (Ukraine). Daily counts of natural and cardio-respiratory mortality were collected for all five cities. Depending on data availability, the following study periods were chosen: Augsburg and Dresden 2011-2012, Ljubljana and Prague 2012-2013, Chernivtsi 2013-March 2014. The associations between air pollutants and health outcomes were assessed using confounder-adjusted Poisson regression models examining single (lag 0-lag 5) and cumulative lags (lag 0-1, lag 2-5, and lag 0-5). City-specific estimates were pooled using meta-analyses methods.

RESULTS

Results indicated a delayed and prolonged association between UFP and respiratory mortality (9.9% [95%-confidence interval: -6.3%; 28.8%] increase in association with a 6-day average increase of 2750particles/cm(3) (average interquartile range across all cities)). Cardiovascular mortality increased by 3.0% [-2.7%; 9.1%] and 4.1% [0.4%; 8.0%] in association with a 12.4μg/m(3) and 4.7μg/m(3) increase in the PM2.5- and PM2.5-10-averages of lag 2-5.

CONCLUSIONS

We observed positive but not statistically significant associations between prolonged exposures to UFP and respiratory mortality, which were independent of particle mass exposures. Further multi-centre studies are needed investigating several years to produce more precise estimates on health effects of UFP.

Changes in the Effect of Heat on Mortality in the Last 20 Years in Nine European Cities. Results from the PHASE Project

The European project PHASE aims to evaluate patterns of change in the temperature–mortality relationship and in the number of deaths attributable to heat in nine European cities in two periods, before and after summer 2003 (1996–2002 and 2004–2010). We performed age-specific Poisson regression models separately in the two periods, controlling for seasonality, air pollution and time trends. Distributed lag non-linear models were used to estimate the Relative Risks of daily mortality for increases in mean temperature from the 75th to 99th percentile of the summer distribution for each city. In the recent period, a reduction in the mortality risk associated to heat was observed only in Athens, Rome and Paris, especially among the elderly. Furthermore, in terms of heat-attributable mortality, 985, 787 and 623 fewer deaths were estimated, respectively, in the three cities. In Helsinki and Stockholm, there is a suggestion of increased heat effect. Noteworthy is that an effect of heat was still present in the recent years in all cities, ranging from +11% to +35%. In Europe, considering the warming observed in recent decades and population ageing, effective intervention measures should be promoted across countries, especially targeting vulnerable subgroups of the population with lower adaptive resources.

Searching for the best modeling specification for assessing the effects of temperature and humidity on health: a time series analysis in three European cities

Epidemiological time series studies suggest daily temperature and humidity are associated with adverse health effects including increased mortality and hospital admissions. However, there is no consensus over which metric or lag best describes the relationships. We investigated which temperature and humidity model specification most adequately predicted mortality in three large European cities. Daily counts of all-cause mortality, minimum, maximum and mean temperature and relative humidity and apparent temperature (a composite measure of ambient and dew point temperature) were assembled for Athens, London, and Rome for 6 years between 1999 and 2005. City-specific Poisson regression models were fitted separately for warm (April-September) and cold (October-March) periods adjusting for seasonality, air pollution, and public holidays. We investigated goodness of model fit for each metric for delayed effects up to 13 days using three model fit criteria: sum of the partial autocorrelation function, AIC, and GCV. No uniformly best index for all cities and seasonal periods was observed. The effects of temperature were uniformly shown to be more prolonged during cold periods and the majority of models suggested separate temperature and humidity variables performed better than apparent temperature in predicting mortality. Our study suggests that the nature of the effects of temperature and humidity on mortality vary between cities for unknown reasons which require further investigation but may relate to city-specific population, socioeconomic, and environmental characteristics. This may have consequences on epidemiological studies and local temperature-related warning systems.

Systematic review of the association between climate and hip fractures

This study aims to systematically review epidemiological studies that evaluate the relationship between meteorology and the incidence of hip fracture (HF). After a search in Scopus, PubMed, and Embase, two independent authors assessed the relevance of studies and extracted data for description. From each study, we extracted the geographic and temporal scope, design, study variables (meteorological and related to HF), statistical analysis, and estimated associations. Of a total of 134 works, 20 studies were selected. All use an ecological design but one case-crossover. Most studies have been conducted in northern latitudes. The analysis methodology did not take into account the temporal structure of the data in 10 studies (regression and linear correlations); the rest used Poisson regression (7) and ARIMA model (3). Most studies showed significant positive associations with rainfall, especially in the form of snow: HF relative risk (RR) on days with precipitation vs. days without precipitation that ranged from 1.14 (95 % confidence interval (CI)1.04 to 1.24) to 1.60 (95 % CI 1.06 to 2.41), the temperature, with RR by one degree Celsius decline from 1.012 (95 % CI 1.004 to 1.020) to 1.030 (95 % CI 1.023 to 1.037), and wind (3) RR FC windiest days vs. calm days: 1.32 (95 % CI 1.10 to 1.58) to 1.35 (95 % CI 0.88 to 2.08). This review shows that analytic methods are very heterogeneous and poorly adapted to the temporary nature of the data. Studies confirm a certain seasonality, with more fractures in winter and meaningful relationships with meteorological conditions typical of this season.

Associations between Meteorological Parameters and Influenza Activity in Berlin (Germany), Ljubljana (Slovenia), Castile and León (Spain) and Israeli Districts

BACKGROUND

Studies in the literature have indicated that the timing of seasonal influenza epidemic varies across latitude, suggesting the involvement of meteorological and environmental conditions in the transmission of influenza. In this study, we investigated the link between meteorological parameters and influenza activity in 9 sub-national areas with temperate and subtropical climates: Berlin (Germany), Ljubljana (Slovenia), Castile and León (Spain) and all 6 districts in Israel.

METHODS

We estimated weekly influenza-associated influenza-like-illness (ILI) or Acute Respiratory Infection (ARI) incidence to represent influenza activity using data from each country's sentinel surveillance during 2000-2011 (Spain) and 2006-2011 (all others). Meteorological data was obtained from ground stations, satellite and assimilated data. Two generalized additive models (GAM) were developed, with one using specific humidity as a covariate and another using minimum temperature. Precipitation and solar radiation were included as additional covariates in both models. The models were adjusted for previous weeks' influenza activity, and were trained separately for each study location.

RESULTS

Influenza activity was inversely associated (p<0.05) with specific humidity in all locations. Minimum temperature was inversely associated with influenza in all 3 temperate locations, but not in all subtropical locations. Inverse associations between influenza and solar radiation were found in most locations. Associations with precipitation were location-dependent and inconclusive. We used the models to estimate influenza activity a week ahead for the 2010/2011 period which was not used in training the models. With exception of Ljubljana and Israel's Haifa District, the models could closely follow the observed data especially during the start and the end of epidemic period. In these locations, correlation coefficients between the observed and estimated ranged between 0.55 to 0.91and the model-estimated influenza peaks were within 3 weeks from the observations.

CONCLUSION

Our study demonstrated the significant link between specific humidity and influenza activity across temperate and subtropical climates, and that inclusion of meteorological parameters in the surveillance system may further our understanding of influenza transmission patterns.

The association between air pollution and weather conditions with increase in the number of admissions of asthmatic patients in emergency wards: a case study in Kermanshah

BACKGROUND

Industrialization and urbanization had a devastating impact on public health and caused an increase in health related morbidity and mortality. In fact, asthma is a chronic condition which is considered as one of the significant challenges of public health. In this study, we investigated the association of air pollution and weather conditions with excess emergency ward admissions of asthmatic patients in Kermanshah hospitals.

METHODS

This was an ecological study. The total number of hospital admissions to emergency wards from all related and major hospitals of Kermanshah was collected from September 2008 through August 2009. In addition, data on air pollution as well as meteorological data were collected from the Environmental Protection Agency and Meteorological Organization of Kermanshah. To determine the association between the number of hospitalization due to asthma with those parameters, Poisson regression was used.

RESULTS

The results of Poisson regression revealed a significant association between carbon monoxide, ozone, nitrogen dioxide and temperature with emergency room visits due to asthma in Kermanshah. No associations were found for sulfur dioxide or for particulate matter.

CONCLUSION

This study provides further evidence for the significant effect of monoxide carbon on asthma; and it suggests that temperature may have a role in the exacerbation of asthma. However, due to the multi-factorial nature of asthma, other factors also play a major role in the development and exacerbation of this illness.

Effect measure modification of blood lead-air lead slope factors

There is abundant literature finding that susceptibility factors, including race and ethnicity, age, and housing, directly influence blood lead levels. No study has explored how susceptibility factors influence the blood lead-air lead relationship nationally. The objective is to evaluate whether susceptibility factors act as effect measure modifiers on the blood lead-air lead relationship. Participant level blood lead data from the 1999 to 2008 National Health and Nutrition Examination Survey were merged with air lead data from the US Environmental Protection Agency. Linear mixed effects models were run with and without an air lead interaction term for age group, sex, housing age, or race/ethnicity to determine whether these factors are effect measure modifiers for all ages combined and for five age brackets. Age group and race/ethnicity were determined to be effect measure modifiers in the all-age model and for some age groups. Being a child (1-5, 6-11, and 12-19 years) or of Mexican-American ethnicity increased the effect estimate. Living in older housing (built before 1950) decreased the effect estimate for all models except for the 1-5-year group, where older housing was an effect measure modifier. These results are consistent with the peer-reviewed literature of time-activity patterns, ventilation, and toxicokinetics.

Associations between short-term exposure to particulate matter and ultrafine particles and myocardial infarction in Augsburg, Germany

BACKGROUND

Short-term exposure to increased particulate matter (PM) concentration has been reported to trigger myocardial infarction (MI). However, the association with ultrafine particles remains unclear.

OBJECTIVES

We aimed to assess the effects of short-term air pollution and especially ultrafine particles on registry-based MI events and coronary deaths in the area of Augsburg, Germany.

METHODS

Between 1995 and 2009, the MONICA/KORA myocardial infarction registry recorded 15,417 cases of MI and coronary deaths. Concentrations of PM<10μm (PM10), PM<2.5μm (PM2.5), particle number concentration (PNC) as indicator for ultrafine particles, and meteorological parameters were measured in the study region. Quasi-Poisson regression adjusting for time trend, temperature, season, and weekday was used to estimate immediate, delayed and cumulative effects of air pollutants on the occurrence of MI. The daily numbers of total MI, nonfatal and fatal events as well as incident and recurrent events were analysed.

RESULTS

We observed a 1.3% risk increase (95%-confidence interval: [-0.9%; 3.6%]) for all events and a 4.4% [-0.4%; 9.4%] risk increase for recurrent events per 24.3μg/m(3) increase in same day PM10 concentrations. Nonfatal events indicated a risk increase of 3.1% [-0.1%; 6.5%] with previous day PM10. No association was seen for PM2.5 which was only available from 1999 on. PNC showed a risk increase of 6.0% [0.6%; 11.7%] for recurrent events per 5529 particles/cm(3) increase in 5-day average PNC.

CONCLUSIONS

Our results suggested an association between short-term PM10 concentration and numbers of MI, especially for nonfatal and recurrent events. For ultrafine particles, risk increases were notably high for recurrent events. Thus, persons who already suffered a MI seemed to be more susceptible to air pollution.

Air pollution, avoidance behaviour and children's respiratory health: evidence from England

Despite progress in air pollution control, concerns remain over the health impact of poor air quality. Governments increasingly issue air quality information to enable vulnerable groups to avoid exposure. Avoidance behaviour potentially biases estimates of the health effects of air pollutants. But avoidance behaviour imposes a cost on individuals and therefore may not be taken in all circumstances. This paper exploits panel data at the English local authority level to estimate the relationship between children's daily hospital emergency admissions for respiratory diseases and common air pollutants, while allowing for avoidance behaviour in response to air pollution warnings. A 1% increase in nitrogen dioxide or ozone concentrations increases hospital admissions by 0.1%. For the subset of asthma admissions - where avoidance is less costly - there is evidence of avoidance behaviour. Ignoring avoidance behaviour, however, does not result in statistically significant underestimation of the health effect of air pollution.

Structured expert judgment to characterize uncertainty between PM2.5 exposure and mortality in Chile

To further the understanding and implementation of expert elicitation methods in the evaluation of public policies related to air pollution, the present study's main goal was to explore the potential strengths and weaknesses of structured expert judgment (SEJ) methodology as a way to derive a C-R function for chronic PM(2.5) exposure and premature mortality in Chile. Local experts were classified in two groups according to background and experience: physicians (Group 1) and engineers (Group 2). Experts were required to provide an estimate of the true percent change in nonaccidental mortality resulting from a permanent 1 μg/m(3) reduction in PM2.5 annual average ambient concentration across the entire Chilean territory. Cooke's Classical Model was used to combine the individual experts' assessments. Experts' mortality estimations varied markedly across groups: while experts in Group 1 delivered higher estimations than those reported in major international cohort studies, estimations from Group 2 were, to varying degrees, anchored to previous studies. Accordingly, combined distributions for each group and all experts were significantly different, due to the high sensitivity of the weighted distribution to experts' performance in calibration variables. Results of this study suggest that, while the use of SEJ has great potential for estimating C-R functions for chronic exposure to PM2.5 and premature mortality and its major sources of uncertainty in countries where no studies are available, its successful implementation is conditioned by a number of factors, which are analyzed and discussed.