A Pilot Study to Quantify Volatile Organic Compounds and Their Sources Inside and Outside Homes in Urban India in Summer and Winter during Normal Daily Activities

Abstract

Indian cities have some of the poorest air quality globally but volatile organic compounds (VOCs)—many of which adversely affect health—and their indoor sources remain understudied in India. In this pilot study we quantified hundreds of VOCs inside and outside 26 homes in Ahmedabad and Gandhinagar, Gujarat, in May 2019 and in January 2020. We sampled in the morning and afternoon/evening to capture temporal variability. Total indoor VOCs were measured at higher concentrations in winter (327.0 ± 224.2 µgm−3) than summer (150.1 ± 121.0 µgm−3) and exceeded those measured outdoors. Using variable reduction techniques, we identified potential sources of compounds (cooking, plastics [with an emphasis on plasticizers], consumer products, siloxanes [as used in the production of consumer products], vehicles). Contributions differed by season and between homes. In May, when temperatures were high, plastics contributed substantially to indoor pollution (mean of 42% contribution to total VOCs) as compared to in January (mean of 4%). Indoor cooking and consumer products contributed on average 29% and 10% to all VOCs indoors in January and 16% and 4% in May. Siloxane sources contributed <4% to any home during either season. Cooking contributed substantially to outdoor VOCs (on average 18% in January and 11% in May) and vehicle-related sources accounted for up to 84% of VOCs in some samples. Overall, results indicate a strong seasonal dependence of indoor VOC concentrations and sources, underscoring the need to better understand factors driving health-harming pollutants inside homes to facilitate exposure reductions.

Temporal Variations in Urban Air Pollution during a 2021 Field Campaign: A Case Study of Ethylene, Benzene, Toluene, and Ozone Levels in Southern Romania

“…Ethylene concentrations at the forested P2 point showed a smaller decrease. The results suggest a strong seasonal dependence, with changes in pollutant concentrations during the day potentially attributed to photochemical reactions of VOCs, fluctuations in temperature and humidity, and pollutant emissions resulting from human activities [55]. F. Meneguzzo et al conducted an investigation using a photoionization detector to analyze the concentrations of total VOCs in various environments in the Italian northern Apennines [56].…”

“…F. Meneguzzo et al conducted an investigation using a photoionization detector to analyze the concentrations of total VOCs in various environments in the Italian northern Apennines [56]. Their findings revealed a peak in VOC concentrations in the early morning and the lowest concentrations in the late afternoon on clear and calm days [55,56]. The study also demonstrated that ethylene, benzene, and toluene exhibited morning peaks (8:30-11:30 a.m.) with decreasing levels in the evening (5:30-8:30 p.m.), as depicted in Figure 4.…”

Indoor Air Quality in Urban India: Current Status, Research Gap, and the Way Forward

“…55 In contrast to IAP studies in developed countries, IAP measurements in India are limited in parameters, duration, spatial locations, and nature of measurements (offline and online). Some IAP studies conducted in India are listed in 29,44 While these species are important, other species, such as O 3 , speciated organics, and chlorinated species, are yet to be measured extensively in urban-Indian built environments. The omission of these gaseous species hinders the understanding of indoor physicochemistry and the full scope of health impacts of IAP.…”

“…Datta et al also included real-time VOC measurements without any further chemical speciation . Offline gaseous measurements included Cl 2 , H 2 S, NH 3 , polycyclic aromatic hydrocarbon (PAH), CS 2 , and chemically speciated VOCs. − , While these species are important, other species, such as O 3 , speciated organics, and chlorinated species, are yet to be measured extensively in urban-Indian built environments. The omission of these gaseous species hinders the understanding of indoor physicochemistry and the full scope of health impacts of IAP.…”

Impact of Indoor Air Pollution in Pakistan—Causes and Management

“…The resulting indoor pollutants have been identified as PM, noxious gases, bacteria, fungi, insects, etc. [25][26][27]. The major indoor toxic gases involve the oxides of carbon (COx) (carbon monoxide (CO) and carbon dioxide (CO 2 )) [28], oxides of nitrogen (NOx) (nitric oxide (NO) and nitrogen dioxide (NO 2 )) [29,30], oxides of sulfur (SOx) (sulfur dioxide (SO 2 )) [31], PM [32][33][34], radon [35,36], volatile organic matter (VOC) [37], carbonaceous aerosols/biological aerosols/microorganisms (bacteria, viruses, fungi) [38][39][40], and pesticides [41].…”