Indoor exposure levels of ammonia in residences, schools, and offices in China from 1980 to 2019: A systematic review

Abstract

Indoor ammonia (NH3) pollution has been paid more and more attention in view of its health risk. However, few studies have investigated the exposure level in the non‐occupational environment in China. This study systematically reviewed the indoor ammonia exposure level in different regions, the equivalent exposure concentration of different populations, and the factors that influence indoor air ammonia in residences, offices, and schools in China. The literature published in 1980–2019 from main databases was searched and detailed screened, and finally, 56 related studies were selected. The results illustrated that the median concentration of indoor air ammonia in residences, offices, and school buildings was 0.21 mg/m3, 0.26 mg/m3, and 0.15 mg/m3. There were 46.4%, 71.4%, and 40% of these samples exceeding the NH3 standard, respectively. The national concentrations and the equivalent exposure levels of adults and children were calculated and found to be higher than 0.20 mg/m3. The concentration of ammonia varied greatly in different climate zones and economic development regions. Higher concentrations were found in the severe cold zone and the regions with higher economic level. This review reveals a high exposure risk of indoor air ammonia and the crucial impact of human emission, indoor air temperature, new concrete, and economic level, suggesting further investigation on indoor air ammonia evaluation and health effects.

Indoor formaldehyde levels in residences, schools, and offices in China in the past 30 years: A systematic review

“…This study is part of the Chinese Burden of Disease Attributable to Indoor Air Pollutants (CBD‐IAP) project 25–27 . This project proposed a unified protocol of systematic review to demonstrate the concentration distribution of different indoor air pollutants and evaluates the burden of diseases caused by these air pollutants.…”

“…To avoid the shortcomings of the previous practice, this study weights the concentration distribution by sample size to estimate indoor formaldehyde concentration and obtains a concentration distribution of indoor formaldehyde in China that can overcome the above shortcomings to some extent. This method can enlarge the sample size based on the distribution characteristics between finite points, generate random concentrations to obtain concentration probability distribution, and better reflect the concentration distribution of indoor formaldehyde in China 25–27,31–33 …”

“…This study is part of the Chinese Burden of Disease Attributable to Indoor Air Pollutants (CBD-IAP) project. [25][26][27] This project proposed a unified protocol of systematic review to demonstrate the concentration distribution of different indoor air pollutants and evaluates the burden of diseases caused by these air pollutants. A systematic review was performed on each indoor air pollutant to summarize its concentration level in different cities from 1980 to 2019 in China.…”

“…This method can enlarge the sample size based on the distribution characteristics between finite points, generate random concentrations to obtain concentration probability distribution, and better reflect the concentration distribution of indoor formaldehyde in China. [25][26][27][31][32][33] (1) ppm = (24.45 ∕ M) × 1000μg ∕ m 3 To perform the Monte Carlo simulations, the concentration distributions of the cited original studies must first be determined.…”

Numerical simulation of pollutant diffusion in public toilets

“…If someone inhales ammonia, the basic physical signs are cough, dizziness, nausea, and other symptoms. Once it is inhaled severely, the pulmonary edema or breathing difficulty may appear [3]. According to the Chinese national standard (hygiene standard for public toilets in Chinese cities, GB/T 17217-2021), the maximum concentration of ammonia in public toilets should be <0.3 mg/m 3 .…”