A Preliminary Study on the Impact of Household Air Pollution on Adult Respiratory Health in Urban and Rural Settings of Jaipur, India

Background

This study aimed to investigate the association between household air pollution and chronic respiratory illness (CRI) in Jaipur, India.

Materials and Methods

A total of 147 participants over 18 years of age from 45 households were randomly included in the study, and follow-up visits were conducted once every fortnight over a three-month period. Spirometry tests were conducted using a portable hand-held digital spirometer. A self-designed, pretested, semi-structured questionnaire was utilized to collect socio-demographic information from the participants. Statistical tests, such as t-tests were used to analyze the association between household air pollution and CRI.

Results

The prevalence of COPD and bronchial asthma was 2% and 4%, respectively. Various risk factors for CRI were identified within households, and only 4 episodes of acute exacerbation of chronic respiratory illness were observed, resulting in no incidence density calculation. The mean values of forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were significantly lower in females (P < 0.001) Also, the mean values of FVC and FEV1 were significantly lower in rural areas (P < 0.005) than urban areas.

Conclusion

Our findings highlight the importance of government and stakeholder action to implement clean air policies and protect respiratory health. Further studies are needed to expand on these findings and delve deeper into understanding the complex interactions between various risk factors and respiratory health in this population.

Short-Term Associations between PM10 and Respiratory Health Effects in Visby, Sweden

The old Swedish city Visby, located on the island Gotland, has, for several years, reported higher PM₁₀ concentrations than any other city in Sweden. In Visby, local limestone is used, both in road paving and as sand used for anti-slip measures, resulting in a clear annual pattern of PM₁₀ with the highest concentrations during winter/spring when studded tires are allowed. This study analyzes the short-term associations between PM₁₀ and daily number of patients with acute respiratory problems (ICD–10 diagnoses: J00–J99) seeking care at the hospital or primary healthcare units in Visby during the period of 2013–2019. The daily mean of PM₁₀ was on average 45 µg m⁻³ during winter/spring and 18 µg m⁻³ during summer/autumn. Four outcome categories were analyzed using quasi-Poisson regression models, stratifying for period and adjusting for calendar variables and weather. An increase in respiratory visits was associated with increasing concentrations in PM₁₀ during the summer/autumn period, most prominent among children, where asthma visits increased by 5% (95% CI: 2–9%) per 10 µg m⁻³ increase in PM₁₀. For the winter/spring period, no significant effects were observed, except for the diagnose group ‘upper airways’ in adults, where respiratory visits increased by 1% (95% CI: 0.1–1.9%) per 10 µg m⁻³ increase. According to the results, limestone in particles seem to be relatively harmless at the exposure concentrations observed in Visby, and this is in line with the results from a few experimental and occupational studies.

Ozone Pollution: A Major Health Hazard Worldwide

Oxides of nitrogen (NO_x) and volatile organic compounds (VOCs) released into the atmosphere can react in the presence of solar irradiation, leading to ozone formation in the troposphere. Historically, before clean air regulations were implemented to control NO_x and VOCs, ozone concentrations were high enough to exert acute effects such as eye and nose irritation, respiratory disease emergencies, and lung function impairment. At or above current regulatory standards, day-to-day variations in ozone concentrations have been positively associated with asthma incidence and daily non-accidental mortality rate. Emerging evidence has shown that both short-term and long-term exposures to ozone, at concentrations below the current regulatory standards, were associated with increased mortality due to respiratory and cardiovascular diseases. The pathophysiology to support the epidemiologic associations between mortality and morbidity and ozone centers at the chemical and toxicological property of ozone as a strong oxidant, being able to induce oxidative damages to cells and the lining fluids of the airways, and immune-inflammatory responses within and beyond the lung. These new findings add substantially to the existing challenges in controlling ozone pollution. For example, in the United States in 2016, 90% of non-compliance to the national ambient air quality standards was due to ozone whereas only 10% was due to particulate matter and other regulated pollutants. Climate change, through creating atmospheric conditions favoring ozone formation, has been and will continue to increase ozone concentrations in many parts of world. Worldwide, ozone is responsible for several hundreds of thousands of premature deaths and tens of millions of asthma-related emergency room visits annually. To combat ozone pollution globally, more aggressive reductions in fossil fuel consumption are needed to cut NO_x and VOCs as well as greenhouse gas emissions. Meanwhile, preventive and therapeutic strategies are needed to alleviate the detrimental effects of ozone especially in more susceptible individuals. Interventional trials in humans are needed to evaluate the efficacy of antioxidants and ozone-scavenging compounds that have shown promising results in animal studies.

Respiratory health effects of exposure to low-NOx unflued gas heaters in the classroom: a double-blind, cluster-randomized, crossover study

BACKGROUND

There are long-standing concerns about adverse effects of gas appliances on respiratory health. However, the potential adverse effect of low-NOx (nitrogen oxide) unflued gas heaters on children's health has not been assessed.

OBJECTIVES

Our goal was to compare the respiratory health effects and air quality consequences of exposure to low-NOx unflued gas heaters with exposure to non-indoor-air-emitting flued gas heaters in school classrooms.

METHODS

We conducted a double-blind, cluster-randomized, crossover study in 400 primary school students attending 22 schools in New South Wales, Australia. Children measured their lung function and recorded symptoms and medication use twice daily. Nitrogen dioxide (NO2) and formaldehyde concentrations were measured in classrooms using passive diffusion badges.

RESULTS

NO2 concentrations were, on average, 1.8 times higher [95% confidence interval (CI), 1.6-2.1] and formaldehyde concentrations were, on average, 9.4 ppb higher (95% CI, 5.7-13.1) during exposure to unflued gas versus flued gas heaters. Exposure to the unflued gas heaters was associated with increased cough reported in the evening [odds ratio (OR) = 1.16; 95% CI, 1.01-1.34] and wheeze reported in the morning (OR = 1.38; 95% CI, 1.04-1.83). The association with wheeze was greater in atopic subjects. There was no evidence of an adverse effect on lung function.

CONCLUSIONS

We conclude that classroom exposure to low-NOx unflued gas heaters causes increased respiratory symptoms, particularly in atopic children, but is not associated with significant decrements in lung function. It is important to seek alternative sources of heating that do not have adverse effects on health.

Fungal levels in the home and allergic rhinitis by 5 years of age

Studies have repeatedly demonstrated that sensitization to fungi, such as Alternaria, is strongly associated with allergic rhinitis and asthma in children. However, the role of exposure to fungi in the development of childhood allergic rhinitis is poorly understood. In a prospective birth cohort of 405 children of asthmatic/allergic parents from metropolitan Boston, Massachusetts, we examined in-home high fungal concentrations (> 90th percentile) measured once within the first 3 months of life as predictors of doctor-diagnosed allergic rhinitis in the first 5 years of life. In multivariate Cox regression analyses, predictors of allergic rhinitis included high levels of dust-borne Aspergillus [hazard ratio (HR) = 3.27; 95% confidence interval (CI), 1.50-7.14], Aureobasidium (HR = 3.04; 95% CI, 1.33-6.93), and yeasts (HR = 2.67; 95% CI, 1.26-5.66). The factors controlled for in these analyses included water damage or mild or mildew in the building during the first year of the child's life, any lower respiratory tract infection in the first year, male sex, African-American race, fall date of birth, and maternal IgE to Alternaria > 0.35 U/mL. Dust-borne Alternaria and nonsporulating and total fungi were also predictors of allergic rhinitis in models excluding other fungi but adjusting for all of the potential confounders listed above. High measured fungal concentrations and reports of water damage, mold, or mildew in homes may predispose children with a family history of asthma or allergy to the development of allergic rhinitis.