The state of indoor air quality in Pakistan—a review

Background and purpose: In Pakistan, almost 70% of the population lives in rural areas. Ninety-four percent of households in rural areas and 58% in urban areas depend on biomass fuels (wood, dung, and agricultural waste). These solid fuels have poor combustion efficiency. Due to incomplete combustion of the biomass fuels, the resulting smoke contains a range of health-deteriorating substances that, at varying concentrations, can pose a serious threat to human health. Indoor air pollution accounts for 28,000 deaths a year and 40 million cases of acute respiratory illness. It places a significant economic burden on Pakistan with an annual cost of 1% of GDP. Despite the mounting evidence of an association between indoor air pollution and ill health, policy makers have paid little attention to it. This review analyzes the existing information on levels of indoor air pollution in Pakistan and suggests suitable intervention methods. Methods: This review is focused on studies of indoor air pollution, due to biomass fuels, in Pakistan published in both scientific journals and by the Government and international organizations. In addition, the importance of environmental tobacco smoke as an indoor pollutant is highlighted. Results: Unlike many other developing countries, there are no long-term studies on the levels of indoor air pollution. The limited studies that have been undertaken indicate that indoor air pollution should be a public health concern. High levels of particulate matter and carbon monoxide have been reported, and generally, women and children are subject to the maximum exposure. There have been a few interventions, with improved stoves, in some areas since 1990. However, the effectiveness of these interventions has not been fully evaluated. Conclusion: Indoor air pollution has a significant impact on the health of the population in Pakistan. The use of biomass fuel as an energy source is the biggest contributor to poor indoor air quality followed by smoking. In order to arrest the increasing levels of indoor pollution, there is a dire need to recognize it as a major health hazard and formulate a national policy to combat it. An integrated effort, with involvement of all stakeholders, could yield promising results. A countrywide public awareness campaign, on the association of indoor air pollution with ill health, followed by practical intervention would be an appropriate approach. Due to the current socioeconomic conditions in the country, development and adoption of improved cooking stoves for the population at large would be the most suitable choice. However, the potential of biogas as a fuel should be explored further, and modern fuels (natural gas and LPG) need to be accessible and economical. Smoking in closed public spaces should be banned, and knowledge of the effect of smoking on indoor air quality needs to be quantified. © 2010 Springer-Verlag

Exposure to extreme heat and precipitation events associated with increased risk of hospitalization for asthma in Maryland, U.S.A.

Several studies have investigated the association between asthma exacerbations and exposures to ambient temperature and precipitation. However, limited data exists regarding how extreme events, projected to grow in frequency, intensity, and duration in the future in response to our changing climate, will impact the risk of hospitalization for asthma. The objective of our study was to quantify the association between frequency of extreme heat and precipitation events and increased risk of hospitalization for asthma in Maryland between 2000 and 2012. We used a time-stratified case-crossover design to examine the association between exposure to extreme heat and precipitation events and risk of hospitalization for asthma (ICD-9 code 493, n = 115,923). Occurrence of extreme heat events in Maryland increased the risk of same day hospitalization for asthma (lag 0) by 3 % (Odds Ratio (OR): 1.03, 95 % Confidence Interval (CI): 1.00, 1.07), with a considerably higher risk observed for extreme heat events that occur during summer months (OR: 1.23, 95 % CI: 1.15, 1.33). Likewise, summertime extreme precipitation events increased the risk of hospitalization for asthma by 11 % in Maryland (OR: 1.11, 95 % CI: 1.06, 1.17). Across age groups, increase in risk for asthma hospitalization from exposure to extreme heat event during the summer months was most pronounced among youth and adults, while those related to extreme precipitation event was highest among ≤4 year olds. Exposure to extreme heat and extreme precipitation events, particularly during summertime, is associated with increased risk of hospitalization for asthma in Maryland. Our results suggest that projected increases in frequency of extreme heat and precipitation event will have significant impact on public health.https://doi.org/10.1186/s12940-016-0142-

Indoor Environmental Differences between Inner City and Suburban Homes of Children with Asthma

We conducted this study to compare environmental exposures in suburban homes of children with asthma to exposures in inner city homes of children with asthma, to better understand important differences of indoor pollutant exposure that might contribute to increased asthma morbidity in the inner city. Indoor PM10, PM2.5, NO2, O3, and airborne and dust allergen levels were measured in the homes of 120 children with asthma, 100 living in inner city Baltimore and 20 living in the surrounding counties. Home conditions and health outcome measures were also compared. The inner city and suburban homes differed in ways that might affect airborne environmental exposures. The inner city homes had more cigarette smoking (67% vs. 5%, p < .001), signs of disrepair (77% vs. 5%, p < .001), and cockroach (64% vs. 0%, p < .001) and mouse (80% vs. 5%, p < .001) infestation. The inner city homes had higher geometric mean (GM) levels (p < .001) of PM10 (47 vs. 18 μg/m3), PM2.5 (34 vs. 8.7 μg/m3), NO2 [19 ppb vs. below detection (BD)], and O3 (1.9 vs. .015 ppb) than suburban homes. The inner city homes had lower GM bedroom dust allergen levels of dust mite (.29 vs. 1.2 μg/g, p = .022), dog (.38 vs. 5.5 μg/g, p < .001) and cat (.75 vs. 2.4 μg/g, p = .039), but higher levels of mouse (3.2 vs. .013 μg/g, p < .001) and cockroach (4.5 vs. .42 U/g, p < .001). The inner city homes also had higher GM airborne mouse allergen levels (.055 vs. .016 ng/m3, p = .002). Compared with the homes of suburban children with asthma, the homes of inner city Baltimore children with asthma had higher levels of airborne pollutants and home characteristics that predispose to greater asthma morbidity

Determinants of Allergen Concentrations in Apartments of Asthmatic Children Living in Public Housing

There is growing evidence linking poor housing conditions and respiratory diseases, including asthma. The association between housing conditions and asthma in the inner city has been attributed in part to cockroach and mouse infestation and the resulting allergen exposures. Multiple social and behavioral factors can influence environmental exposures and health conditions, necessitating a thorough examination of such factors. As part of the Healthy Public Housing Initiative, we evaluated the association between physical and household characteristics and pest-related allergen levels in three public housing developments in Boston, MA. We detected cockroach allergens (Bla g 1 and Bla g 2) in bedroom air, bed, and especially high concentrations in kitchen samples. In multivariate Tobit regressions controlling for development and season, clutter and lack of cleanliness in the apartment were associated with a tenfold increase in Bla g 1 concentration in the air, a sevenfold increase in Bla g 1 and an eightfold increase in Bla g 2 concentrations in the bed, and an 11-fold increase in Bla g 2 in the kitchen (p<0.05 for all). Holes in the wall/ceiling were associated with a six- to 11-fold increase in kitchen cockroach allergen concentrations (p<0.05). Occupancy in an apartment unit of 2 years or more was also associated with increased cockroach allergen concentrations. In contrast, there were low concentrations of mouse urinary protein in this population. In conclusion, these results suggest that interventions in these homes should focus on reducing cockroach allergen concentrations and that building-wide interventions should be supplemented with targeted efforts focused on high-risk units