Review of the effect of air pollution exposure from industrial point sources on asthma-related effects in childhood

Assessing environmental injustice in Kansas City by linking paediatric asthma to local sources of pollution: a cross-sectional study

OBJECTIVE

A grassroots environmental-justice organisation in Kansas City has been examining the disproportionate exposure to air pollution experienced by residents living fenceline to the largest classification railyard in the USA. Prior analyses showed limited increased risk for asthma exacerbation for patients with asthma living closer to toxic release inventory (TRI) facilities and railyards. In this study, we assessed geographical asthma and environmental disparities, to further explore community-level disparities.

DESIGN

This is a cross-sectional study of population-level asthma rates, which included rates for all asthma encounters and acute asthma encounters (urgent care, emergency department, inpatient admission). Distances from census-tract centroids to nearest TRI facilities, railyards and highways were calculated. The association between asthma rates and distances was examined using Kendall's τ correlation and multivariable Poisson regression models.

SETTING

We used electronic medical record data from the regional paediatric hospital, census and Environmental Protection Agency (EPA) air monitoring data.

PARTICIPANTS

Patients with 2+ asthma encounters during the EPA study timeframe were identified.

RESULTS

Residential distance from railyards exhibited a significant negative correlation with overall (-0.36 (CI -0.41 to -0.32)) and acute (-0.27 (CI -0.32 to -0.22)) asthma rates. Asthma rates were elevated among tracts north of the closest railyard (incident rate ratio: 1.38; CI 1.35 to 1.41) when compared with southern directionality. An increased distance from the nearest railyard of 3 km was associated with a decrease in overall asthma rates of 26%.

CONCLUSION

Significant negative associations between proximity to all pollution source types and asthma rates were observed. This community-level research has served as a tool for community engagement and will be used to support proposed local policy. Environmental justice work addresses local concerns involving small, limited datasets, if the data exist at all. The academic epidemiological platform may reconsider acceptable approaches to small population research in order to better serve communities with the most need.

Neighborhood-level variability in asthma-related emergency department visits in Central Texas

BACKGROUND

The extent to which incidence rates of asthma-related emergency department (ED) visits vary from neighborhood to neighborhood and predictors of neighborhood-level asthma ED visit burden are not well understood.

OBJECTIVE

We aimed to describe the census tract-level spatial distribution of asthma-related ED visits in Central Texas and identify neighborhood-level characteristics that explain variability in neighborhood-level asthma ED visit rates.

METHODS

Conditional autoregressive models were used to examine the spatial distribution of asthma-related ED visit incidence rates across census tracts in Travis County, Texas, and assess the contribution of census tract characteristics to their distribution.

RESULTS

There were distinct patterns in ED visit incidence rates at the census tract scale. These patterns were largely unexplained by socioeconomic or selected built environment neighborhood characteristics. However, racial and ethnic composition explained 33% of the variability of ED visit incidence rates across census tracts. The census tract predictors of ED visit incidence rates differed by racial and ethnic group.

CONCLUSIONS

Variability in asthma ED visit incidence rates are apparent at smaller spatial scales. Most of the variability in census tract-level asthma ED visit rates in Central Texas is not explained by racial and ethnic composition or other neighborhood characteristics.

Changes in industrial air pollution and the onset of childhood asthma in Quebec, Canada

Ambient air pollution has been associated with asthma onset and exacerbation in children. Whether improvement in air quality due to reduced industrial emissions has resulted in improved health outcomes such as asthma in some localities has usually been assessed indirectly with studies on between-subject comparisons of air pollution from all sources and health outcomes. In this study we directly assessed, within small areas in the province of Quebec (Canada), the influence of changes in local industrial fine particulate matter (PM2.5), nitrogen dioxide (NO2), and sulfur dioxide (SO2) concentrations, on changes in annual asthma onset rates in children (≤12 years old) with a longitudinal ecological design. We identified the yearly number of new cases of childhood asthma in 1282 small areas (census tracts or local community service centers) for the years 2002, 2004, 2005, 2006, and 2015. Annual average concentrations of industrial air pollutants for each of the geographic areas, and three sectors (i.e., pulp and paper mills, petroleum refineries, and metal smelters) were estimated by the Polair3D chemical transport model. Fixed-effects negative binomial models adjusted for household income were used to assess associations; additional adjustments for environmental tobacco smoke, background pollutant concentrations, vegetation coverage, and sociodemographic characteristics were conducted in sensitivity analyses. The incidence rate ratios (IRR) for childhood asthma onset for the interquartile increase in total industrial PM2.5, NO2, and SO2 were 1.016 (95% confidence interval, CI: 1.006-1.026), 1.063 (1.045-1.090), and 1.048 (1.031-1.080), respectively. Positive associations were also found with pollutant concentrations from most individual sectors. Results suggest that changes in industrial pollutant concentrations influence childhood asthma onset rates in small localities.

Associations between Paternal Co-residence and Child Health among African American Children

We investigated the associations between paternal co-residence and asthma, obesity, and blood pressure among children aged 3-5 years. Mother/child dyads (N = 250) self-identified as African American or Black. Mothers reported on father's co-residence and child's asthma diagnosis. Height, weight, and blood pressure were measured. Regression models were used to examine paternal co-residence with child health outcomes (i.e., asthma, obesity, and blood pressure). Confounders included maternal and child age, child sex, maternal smoking, and insurance status. Children who lived with their fathers were less likely to have asthma (OR = 0.39, 95% CI 0.18-0.79), though this association was not significant after adjustment for confounders (aOR = 0.47, 95% CI 0.22-1.01). Paternal co-residence was not significantly associated with child obesity (aOR = 0.78, 95% CI 0.35-1.73), systolic (β = 0.57, SE = 1.2, p = .64), or diastolic (β = 1.91, SE = 1.0, p = .07) blood pressure. More research is necessary to understand the diversity of family living situations and how they affect child health.

Environmental inequality: Air pollution and asthma in children

INTRODUCTION

Whether you benefit from high-quality urban environments, such as those rich in green and blue spaces, that may offer benefits to allergic and respiratory health depends on where you live and work. Environmental inequality, therefore, results from the unequal distribution of the risks and benefits that stem from interactions with our environment.

METHODS

Within this perspective, this article reviews the evidence for an association between air pollution caused by industrial activities, traffic, disinfection-by-products, and tobacco/e-cigarettes, and asthma in children. We also discuss the proposed mechanisms by which air pollution increases asthma risk, including environmental epigenetic regulations, oxidative stress, and damage, disrupted barrier integrity, inflammatory pathways, and enhancement of respiratory sensitization to aeroallergens.

RESULTS AND CONCLUSIONS

Environmental air pollution is a major determinant of childhood asthma, but the magnitude of effect is not shared equally across the population, regions, and settings where people live, work, and spend their time. Improvement of the exposure assessment, a better understanding of critical exposure time windows, underlying mechanisms, and drivers of heterogeneity may improve the risk estimates. Urban conditions and air quality are not only important features for national and local authorities to shape healthy cities and protect their citizens from environmental and health risks, but they also provide opportunities to mitigate inequalities in the most deprived areas where the environmental burden is highest. Actions to avoid exposure to indoor and outdoor air pollutants should be complementary at different levels-individual, local, and national levels-to take effective measures to protect children who have little or no control over the air they breathe.

Fluorine-implanted indium-gallium-zinc oxide (IGZO) chemiresistor sensor for high-response NO2 detection

Gas sensors fabricated using In-Ga-Zn oxide (IGZO) thin films doped with Fluorine (F) were used to detect nitrogen dioxide (NO₂) gas. IGZO films with a thickness of 250 nm were deposited onto SiO₂/Si substrates via radio-frequency magnetron sputtering, followed by F-doping by an ion-implantation procedure with implant energy of 45 keV and a dose of 3 × 10¹⁵ ions/cm². The NO₂ gas detection performance of the fabricated thin-film sensors was tested at various temperatures and NO₂ concentrations. The F-doped IGZO (F-IGZO) sensor showed high NO₂ gas sensitivity: the ratio between the responses to NO₂ and air (R_gas/R_air) was 590 at 250 °C and 100 ppm NO₂ gas concentration. F-IGZO sensor showed superior selectivity toward NO₂ over other gases. The stability of the sensor was also investigated; the sensor was observed to exhibit stable performance for 2 weeks.

RETRACTED: Neighborhood-level variability in asthma-related emergency department visits in Central Texas

Background:

The extent to which asthma-related ED visit incidence rates vary from neighborhood to neighborhood and predictors of neighorbood-level asthma ED visit burden are not well understood.

Objective:

To describe the census tract-level spatial distribution of asthma-related emergency department visits in Central Texas and identify neighborhood-level characteristics that explain variability in neighborhood-level asthma ED visit rates.

Methods:

Conditional autoregressive models were used to examine the spatial distribution of asthma-related ED visit incidence rates across Travis County, TX census tracts and to assess the contribution of census tract characteristics to their distribution.

Results:

There were distinct patterns in ED visit incidence rates at the census tract scale, which were largely unexplained by socioeconomic or selected built environment neighborhood characteristics. Racial and ethnic composition explained 33% of the variability of ED visit incidence rates across census tracts. Spatial patterns and the census tract predictors of ED visit incidence rates differed by racial and ethnic groups.

Conclusions:

Variability in asthma ED visit incidence rates are apparent at a smaller spatial scales than previously examined. The majority of the variability in census tract-level asthma ED visit rates in Central Texas is not explained by racial and ethnic composition or other neighborhood features. Race/ethnicity-specific estimates of neighborhood ED visit rates may be useful for identifying high burden neighborhoods for specific ethnic/racial groups, which otherwise would go unrecognized.

Asthma ED visit rates may vary among neighborhoods; neighborhood-level interventions or moving to a low incidence neighborhood may be effective in reducing asthma disparities and deserve further study.

Air pollution from industries and asthma onset in childhood: A population-based birth cohort study using dispersion modeling

BACKGROUND

Despite evidence that ambient air pollution may play a role in the development of asthma, little is known about the potential contribution of industrial emissions.

OBJECTIVE

We used a population-based birth cohort to investigate the association between asthma onset in childhood and residential exposure to industrial emissions, estimated from atmospheric dispersion modeling.

METHODS

The study population comprised all children born in the province of Quebec, Canada, 2002-2011. Asthma onset were ascertained from health administrative databases with validated algorithms. We used atmospheric dispersion modeling to develop time-varying annual mean concentration of ambient PM_2.5, NO₂ and SO₂ at participants' residence from industries. For each pollutant, we assessed the association between industrial emissions exposure and childhood asthma onset using Cox proportional hazard model, adjusted for sex, material and social deprivation and calendar year. Sensitivity analysis included adjusting for long-term regional and traffic-related ambient PM_2.5 and NO₂, and assessing potential confounding by unmeasured secondhand smoke.

RESULTS

The cohort included 722,667 children and 66,559 incident cases of asthma. For all pollutants, we found a non-linear association between childhood asthma onset and residential ambient air pollutant concentration from industries, with stronger effects at lower concentrations. A change from 25th to the 75th percentile in the mean annual ambient concentration of PM_2.5 (0.13 μg/m³), NO₂ (1.0 μg/m³) and SO₂ (1.6 μg/m³) from industrial emissions was associated with a 19% (95% CI: 17-20%), 21% (95% CI: 19-23%) and 23% (95% CI: 21-24%) increase in the risk of asthma onset in children, respectively. For PM_2.5 and NO₂, associations were persisting after adjustments for long-term regional PM_2.5 and traffic-related NO₂ ambient concentration.

CONCLUSION

Residential exposure to industrial emissions estimated from dispersion modeling was associated with asthma onset in childhood. Importantly, associations were stronger at lower concentrations and independent from those of other sources, thus adding up to the burden of regional and traffic-related air pollution.