Indoor exposure levels of radon in dwellings, schools, and offices in China from 2000 to 2020: A systematic review

Abstract

After decades of development, the indoor environment in China has changed. A systematic review was conducted from peer-reviewed scientific papers with field test data of indoor radon in China from 2000 to 2020 for three types of buildings. The mean concentrations of indoor radon for dwellings, school buildings, and office buildings are 54.6, 56.1, and 54.9 Bq/m 3 . The indoor radon concentration was related to seasons, climate regions, ventilation, decoration, and other factors such as soil and outdoor air. Colder seasons, especially in severe colder areas of China, newer decorated buildings, closed windows, and doors were all associated with higher indoor radon concentrations. Variables like climate region and ventilation showed statistical significance in the correlation analysis. Regarding the increasing trend of indoor radon concentration in China during the last two decades, further study of indoor radon is necessary especially for school buildings and office buildings, and will help access its environmental burden of disease in China more accurately.

Burden of lung cancer attributable to household air pollution in the Chinese female population: trend analysis from 1990 to 2019 and future predictions

“…The AAPCs of the age-standardized mortality and DALYs rates were 0.79% and 0.33%, respectively, and the APCs were 2.42% and 2.31% from 2016 to 2019, respectively. These results imply that the annual average growth rate was high in recent years, which was consistent with the increasing trend of indoor radon concentration in China during the last two decades 8 . However, indoor radon concentrations vary greatly between different areas.…”

“…In terms of residential radon, the overall difference in burden of lung cancer between China and the world increased. In 2019, the Chinese age-standardized mortality and DALYs rates were about 40% higher than the global rates, which may be related to the changes in living and working styles, building types, construction and decorative materials, furniture, and fuel types in recent years 8,32 .…”

“…Globally, the burden of lung cancer and summary exposure values of residential radon increased significantly each year from 1990 to 2019 3 . A systematic review estimated that the mean concentrations of indoor radon in China from 2000 to 2020 for housings, school buildings, and office buildings were 54.6, 56.1, and 54.9Bq/m 3 , respectively, which were much higher than the concentrations of the outdoor environment 8 . The average indoor activity time of Chinese adults accounts for about 81% of each entire day 12 .…”

“…Nevertheless, 2.31 million people die from the combustion of household solid fuels each year, making it the 10th leading risk factor for the loss of DALYs globally 3,7 . Moreover, radon is a common and critical air pollutant in indoor environments that is mainly generated from water sources, fuels (e.g., coal and liquefied gas), soil, construction materials, and decorative materials 8,9 . The Environmental Burden of Disease in European Countries identified radon as one of the main indoor risk factors 10 .…”

Public toilets with insufficient ventilation present high cross infection risk

“…EU standard EN16798-1 recommends applying 10 L/s/person of ventilation (ventilation rate) in an isolated space or keeping the exhaust fan running continuously to ensure effective ventilation 10 . However, to reduce the spread of the SARS-CoV-2 virus over short distances, the ventilation flow rate should be no less than 3L/s/person 11 . Aerosols emitted by a carrier may remain airborne for a certain period before settling and if the toilets lack proper or sufficient ventilation it becomes a situation for potential cross-infection.…”