Residential Air Quality Research Articles

Degradation in urban air quality from construction activity and increased traffic arising from a road widening scheme

Road widening schemes in urban areas are often proposed as a solution to traffic congestion and as a means of stimulating economic growth. There is however clear evidence that new or expanded roads rapidly fill with either displaced or induced traffic, offsetting any short-term gains in eased traffic flows. What has not been addressed in any great detail is the impact of such schemes on air quality, with modelled impact predictions seldom validated by measurements after the expansion of road capacity. In this study we made use of a road widening project in London to investigate the impact on ambient air quality (particulate matter, NOX, NO2) during and after the completion of the road works.PM10 increased during the construction period up to 15μgm−3 during working hours compared to concentrations before the road works. A box modelling approach was used to determine a median emission factor of 0.0022kgPM10m−2month−1, three times larger than that used in the UK emission inventory (0.0007kgPM10m−2month−1). Peaks of activity released 0.0130kgPM10m−2month−1, three and eight times smaller than the peak values used in the European and US inventories. After the completion of the widening there was an increase in all pollutants from the road during rush hour: 2–4μgm−3 for PM10; 1μgm−3 for PM2.5; 40 and 8μgm−3 for NOX and NO2, respectively. NO2 EU Limit Value was breached after the road development illustrating a notable deterioration in residential air quality. Additionally, PM10, but not PM2.5, glutathione dependent oxidative potential increased after the road was widened consistent with an increase in pro-oxidant components in the coarse particle mode, related to vehicle abrasion processes. These increased air pollution indices were associated with an increase in the number of cars, taxis and LGVs.

Effects of Residential Indoor Air Quality and Household Ventilation on Preterm Birth and Term Low Birth Weight in Los Angeles County, California

The purpose of our study was to examine the effects of indoor residential air quality on preterm birth and term low birth weight (LBW). We evaluated 1761 nonsmoking women from a case-control survey of mothers who delivered a baby in 2003 in Los Angeles County, California. In multinomial logistic regression models adjusted for maternal age, education, race/ethnicity, parity and birthplace, we evaluated the effects of living with smokers or using personal or household products that may contain volatile organic compounds and examined the influence of household ventilation. Compared with unexposed mothers, women exposed to secondhand smoke (SHS) at home had increased odds of term LBW (adjusted odds ratio [OR] = 1.36; 95% confidence interval [CI] = 0.85, 2.18) and preterm birth (adjusted OR = 1.27; 95% CI = 0.95, 1.70), although 95% CIs included the null. No increase in risk was observed for SHS-exposed mothers reporting moderate or high window ventilation. Associations were also observed for product usage, but only for women reporting low or no window ventilation. Residential window ventilation may mitigate the effects of indoor air pollution among pregnant women in Los Angeles County, California.

Assessment of Indoor Air Pollution in Homes with Infants

Infants spend most of their indoor time at home; however, residential air quality is poorly understood. We investigated the air quality of infants’ homes in the New England area of the U.S. Participants (N = 53) were parents of infants (0–6 months) who completed telephone surveys to identify potential pollutant sources in their residence. Carbon monoxide (CO), carbon dioxide (CO2), particulate matter with aerodynamic diameter ≤0.5 µm (PM0.5), and total volatile organic compounds (TVOCs) were measured in 10 homes over 4–7 days, and levels were compared with health-based guidelines. Pollutant levels varied substantially across homes and within homes with overall levels for some homes up to 20 times higher than for other homes. Average levels were 0.85 ppm, 663.2 ppm, 18.7 µg/m3, and 1626 µg/m3 for CO, CO2, PM0.5, and TVOCs, respectively. CO2, TVOCs, and PM0.5 levels exceeded health-based indoor air quality guidelines. Survey results suggest that nursery renovations and related potential pollutant sources may be associated with differences in urbanicity, income, and presence of older children with respiratory ailments, which could potentially confound health studies. While there are no standards for indoor residential air quality, our findings suggest that additional research is needed to assess indoor pollution exposure for infants, which may be a vulnerable population.

Application of Participant-based Approach for Residential Air Quality Monitoring

PP-30-193 Background/Aims: Exposure to hazardous pollutants during pregnancy may cause critical reproductive health outcomes. Collecting residential exposure data has been hampered by the cost and participant burden in health studies of indoor air pollution. This study utilized a participant-based approach to measure residential volatile organic compounds concentration. Methods: Four hundred thirteen women were recruited from 3 major hospitals in Seoul and 411 agreed to participate. A passive sampler (OVM 3500, 3M) with instruction and a questionnaire were given to the participants. They were asked to deploy the sampler for 3 to 5 days and return by pre-stamped envelope. Results: A total of 345 participants (83.9%) completed the air sampling and returned the sampler and 16.1% did not return either the sampler or questionnaire. Among the 345 participants who completed sampling, 3 participants returned the sampler but took more than 2 months and 22 participants exposed the sampler for more than 8 days. Among the returned samplers, 92.8% complied with our monitoring quality criteria. The compliance rates were 93.3%, 91.1%, and 94.4% in the 3 hospitals. The mean total volatile organic compounds concentration was 523 μg/m3; 38.4% of residential level exceeded standard of 500 μg/m3 for public use indoors in Korea. The mean concentrations of benzene, toluene, ethyl benzene, and xylenes were 1.0 μg/m3, 53.0 μg/m3, 4.8 μg/m3, and 7.7 μg/m3, respectively. Conclusion: The findings suggest that participant-based sampling approach may be a feasible and cost-effective alternative to residential exposure assessment.

The impact of wood stove technology upgrades on indoor residential air quality

Fine particulate matter (PM 2.5) air pollution has been linked to adverse health impacts, and combustion sources including residential wood-burning may play an important role in some regions. Recent evidence suggests that indoor air quality may improve in homes where older, non-certified wood stoves are exchanged for lower emissions EPA-certified alternatives. As part of a wood stove exchange program in northern British Columbia, Canada, we sampled outdoor and indoor air at 15 homes during 6-day sampling sessions both before and after non-certified wood stoves were exchanged. During each sampling session two consecutive 3-day PM 2.5 samples were collected onto Teflon filters, which were weighed and analyzed for the wood smoke tracer levoglucosan. Residential PM 2.5 infiltration efficiencies ( F inf) were estimated from continuous light scattering measurements made with nephelometers, and estimates of F inf were used to calculate the outdoor- and indoor-generated contributions to indoor air. There was not a consistent relationship between stove technology and outdoor or indoor concentrations of PM 2.5 or levoglucosan. Mean F inf estimates were low and similar during pre- and post-exchange periods (0.32 ± 0.17 and 0.33 ± 0.17, respectively). Indoor sources contributed the majority (∼65%) of the indoor PM 2.5 concentrations, independent of stove technology, although low indoor-outdoor levoglucosan ratios (median ≤ 0.19) and low indoor PM 2.5-levoglucosan correlations ( r ≤ 0.19) suggested that wood smoke was not a major indoor PM 2.5 source in most of these homes. In summary, despite the potential for extensive wood stove exchange programs to reduce outdoor PM 2.5 concentrations in wood smoke-impacted communities, we did not find a consistent relationship between stove technology upgrades and indoor air quality improvements in homes where stoves were exchanged.

Effects of home residential setting, air quality, and season on emergency department (ED) revisits for children with asthma

Effects of home residential setting, air quality, and season on emergency department (ED) revisits for children with asthma

The Self‐Cleaning Oven: A Source of Inside Air Contamination

This exploratory study addressed the question of whether significant amounts of con taminating aerosol pass through the smoke eliminator of the self‐cleaning oven in terms of the impact on normal residential air quality. Data were collected by sampling the emissions of three ovens operating through their design self‐cleaning cycles after being soiled in accordance with an accepted industry standard.The stain/haze potential of the emissions of two of the three ovens would cause significant increases in the normal level of light‐scattering aerosol in a 1360‐ft.3 room. One range would have created a haze level found objectionable by previous researchers. Reduction of the soil level by one‐half resulted in a lesser reduction in light‐scattering aerosol for one range, but a far greater reduction for the other two ranges. The first few self‐cleaning cycles may produce extremely large quantities of smoke, due to the burning off of insulation oils and binders.

The effects of woodburning on the indoor residential air quality

Data from suburban residences in the Boston metropolitan area reveal a potential adverse impact on indoor air quality from woodburning in woodstoves and fireplaces. Ambient pollutant concentrations at each residence were compared to corresponding pollutant levels indoors at three locations (kitchen, bedroom, and activity room). Individual gaseous pollutant samples were averaged on an hourly basis while 24-h integrated samples of particulate matter were obtained. Ten gaseous pollutants were sampled along with total suspended particulates (TSP). Chemical analyses further determined ten components of TSP including trace metals, benzo- a-pyrene(B) aP, respirable suspended particulates (RSP), and water soluble sulfates and nitrates. Monitoring lasted two weeks at each residence and was conducted under occupied, real-life, conditions. Observed, elevated indoor concentrations of TSP, RSP, and B aP are attributed to woodburning. Data indicate that average indoor TSP concentrations during woodburning periods were about three times corresponding levels during nonwoodburning periods. The primary 24-h national ambient air quality standard (NAAQS) for TSP was exceeded once indoors during fireplace use, and the secondary, 24-h TSP NAAQS, was also exceeded indoors by RSP concentrations. Indoor B aP concentrations during woodstove use averaged five times more than during nonwoodburning periods. At this stage, results are only indicative, but the potential impact from elevated indoor concentrations of TSP, RSP, and B aP, attributed to woodburning, may have long-term health implications.