Exposure to particulate matter and ozone of outdoor origin in Singapore

Gall, Elliott T.; Chen, Ailu; Chang, Victor Wei-Chung; Nazaroff, William W.

doi:10.1016/j.buildenv.2015.03.027

Cited by 25 publications

(13 citation statements)

References 47 publications

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“…Participants spent the large majority of their time in three microenvironment categories: 61% at home, 26% at work, 7% in transit, and spent only 1% outdoors. These time-activity budget values agree reasonably well with a recent modeling study of exposures to particulate matter and ozone in Singapore that reported 70%, 28%, 3.2%, and 4.5%, at home, at work, transit, and outdoors respectively [29]. Differences in daily integrated CO2 exposures appear not to be driven by differences in behavior across groups as no statistically significant differences in comparisons of timemicroenvironment-activity budgets are observed (see Table S3 in the SI).…”

Section: Estimates Of Time Integrated Co2 Exposures and Time Activitysupporting

confidence: 79%

Real-time monitoring of personal exposures to carbon dioxide

Gall

Cheung

Luhung

et al. 2016

Building and Environment

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Elevated indoor CO2 levels are indicative of insufficient ventilation in occupied spaces and correlate with elevated concentrations of pollutants of indoor origin. Adverse health and wellbeing outcomes associated with elevated indoor CO2 levels are based on CO2 as a proxy, although some emerging evidence suggests CO2 itself may impact human cognition. Using portable monitors, we conducted an exposure study with 16 subjects in Singapore to understand the levels, dynamics and influencing factors of personal exposure to CO2. Participants carried a CO2 monitor continuously for 7-day periods recording their exposure levels at 1-min intervals. A recall diary was maintained of time-microenvironment-activity budget. We found that the mode of bedroom ventilation was a major determinant of CO2 exposure. Approximately half of the participants slept in bedrooms employing ductless split air-conditioners (group "AC"); half slept in bedrooms naturally ventilated through operable windows (group "NV"). Median CO2 exposure levels for AC vs. NV groups are significantly different (̃ = 650 ppm vs. ̃ = 550 ppm, p < 0.001). Mean daily integrated exposures for group AC were statistically higher than for group NV: 22,800 ppm h/d vs. 16,000 ppm h/d (p < 0.005). Exposure events associated with potential adverse cognitive implications (duration > 2.5 h, average CO2 mixing ratio > 1000 ppm) occurred, on average, at frequencies of 0.5 d -1 across all participants, 0.6 d -1 for AC participants and 0.2 d -1 for NV participants. The majority of such events occurred in the home (86%), followed by work (9%) and transit (3%).

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Section: Estimates Of Time Integrated Co2 Exposures and Time Activitysupporting

confidence: 79%

Real-time monitoring of personal exposures to carbon dioxide

Gall

Cheung

Luhung

et al. 2016

Building and Environment

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“…Ambient air pollutants containing copper, iron, potassium, nickel, silicon, vanadium, and zinc, with a particle size of between 2.5 and 10 microns, and ozone gas easily find their way into these houses through the natural ventilation, in turn contributing to household air pollution 12 . In particular, houses that are close to traffic-heavy roads, which are populated with vehicles using diesel as fuel, tend to have a higher load of household air pollutants.…”

Section: Sources Of Household Air Pollutionmentioning

confidence: 99%

Household air pollution and its effects on health

Apte¹,

Salvi²

2016

F1000Res

139

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Household air pollution is a leading cause of disability-adjusted life years in Southeast Asia and the third leading cause of disability-adjusted life years globally. There are at least sixty sources of household air pollution, and these vary from country to country. Indoor tobacco smoking, construction material used in building houses, fuel used for cooking, heating and lighting, use of incense and various forms of mosquito repellents, use of pesticides and chemicals used for cleaning at home, and use of artificial fragrances are some of the various sources that contribute to household air pollution. Household air pollution affects all stages of life with multi-systemic health effects, and its effects are evident right from pre-conception to old age. In utero exposure to household air pollutants has been shown to have health effects which resonate over the entire lifetime. Exposures to indoor air pollutants in early childhood also tend to have repercussions throughout life. The respiratory system bears the maximum brunt, but effects on the cardiovascular system, endocrine system, and nervous system are largely underplayed. Household air pollutants have also been implicated in the development of various types of cancers. Identifying household air pollutants and their health implications helps us prepare for various health-related issues. However, the real challenge is adopting changes to reduce the health effects of household air pollution and designing innovative interventions to minimize the risk of further exposure. This review is an attempt to understand the various sources of household air pollution, the effects on health, and strategies to deal with this emergent risk factor of global mortality and morbidity.

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“…This was particularly preferred for extended population studies, as well as for economic reasons. However, as these measurements do not take into account the existence of a personal cloud of each individual, they usually result in poor correlations of personal exposure with ambient concentrations [14][15][16][17][18]. These limitations were overtaken by the development of light-weight passive ozone samplers [19] for the assessment of personal exposure to O 3 , which have been used to a large extent since then [3,5,17,18,[20][21][22][23][24][25], and still comprise a reliable [26] and cost-effective method.…”

Section: Introductionmentioning

confidence: 99%

Commuters’ Personal Exposure to Ambient and Indoor Ozone in Athens, Greece

2017

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This pilot study aimed to monitor the residential/office indoor, outdoor, and personal levels of ozone for people living, working, and commuting in Athens, Greece. Participants (16 persons) of this study worked at the same place. Passive sampling analysis results did not indicate any limit exceedance (Directive 2008/50/EC: 120 µg/m 3 , World Health Organization (WHO) Air Quality Guidelines 2005: 100 µg/m 3 ). The highest "house-outdoor" concentration was noticed for participants living in the north suburbs of Athens, confirming the photochemical ozone formation at the northern parts of the basin during southwestern prevailing winds. The residential indoor to outdoor ratio (I/O) was found to be significantly lower than unity, underlying the outdoor originality of the pollutant. The highest "office-indoor" concentration was observed in a ground-level building, characterized by the extensive use of photocopy machines and printers. Personal ozone levels were positively correlated only with indoor-office concentrations. A clear correlation of personal ozone levels to the time spent by the individuals during moving/staying outdoors was observed. On the other hand, no correlation was observed when focusing only on commuting time, due to the fact that transit time includes both on-foot and in-vehicle time periods, therefore activities associated with increased exposure levels, but also with pollutants removal by recirculating air filtering systems, respectively.

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Exposure to particulate matter and ozone of outdoor origin in Singapore

Cited by 25 publications

References 47 publications

Real-time monitoring of personal exposures to carbon dioxide

Real-time monitoring of personal exposures to carbon dioxide

Household air pollution and its effects on health

Commuters’ Personal Exposure to Ambient and Indoor Ozone in Athens, Greece

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