Indoor PM2.5 concentrations in residential buildings during a severely polluted winter: A case study in Tianjin, China

A Review of Recent Advances in Research on PM2.5 in China

“…Li et al [ 81 ] concluded that PM 2.5 concentration in households using coal to cook was significantly higher than those using gas or electricity, and if coal is switched to gas or electricity, the PM 2.5 concentration in the kitchen could be reduced by 40–70%. Zhou et al [ 82 ] indicated that human activities such as walking, dressing and cleaning could result in increased indoor PM 2.5 concentration by 33%. Gui et al [ 83 ] conducted experiments on dry-sweeping, wet-sweeping and air-dry sweeping in an office.…”

“…), indoor sources of pollution, the conditions of the building envelope itself (the airtightness of the outer windows, the degree of sealing performance of the outer window with the wall, cracks over the wall, etc. ), and the air changes per hour (ACH) [ 76 , 82 , 169 , 170 , 171 , 172 , 173 , 174 , 175 ]. Lin et al [ 173 ] explored the difference of PM 2.5 pollution in Wuhan and Guangzhou.…”

Indoor secondary organic aerosols formation from ozonolysis of monoterpene: An example of d-limonene with ammonia and potential impacts on pulmonary inflammations

“…Higher levels of many pollutants were often seen indoor than outdoor (He et al, 2005;Jones et al, 2000;Parker et al, 2008;Zhou et al, 2016). The United States Environmental Protection Agency (U.S. EPA) highlighted that people spend approximately 90% of their lifetime in indoor environments.…”

Retrofitting existing buildings to control indoor PM2.5 concentration on smog days: Initial experience of residential buildings in China

“…Chen and Zhao 15 described the PM 2.5 concentration relationship between indoors and outdoors in detail using different concepts such as indoor/outdoor (I/O) ratio, infiltration factor and penetration factor. Studies also focused on the factors influencing indoor PM 2.5 concentration, such as meteorological parameters including wind speed, wind direction, temperature and relative humidity relating to outdoor PM 2.5 concentration; 16 indoor emission sources such as smoking, cooking and human disturbance; 10 penetration factor and deposition factor; [17][18][19] infiltration with different openings to the external environment (airtightness); filter efficiency of the makeup air and indoor recirculated air (air purifier) 20,21 and ventilation systems. [22][23][24][25] Some building retrofit measures have been proposed by many researchers to reduce indoor PM 2.5 concentrations, on the basis of the study of the influential factors mentioned above.…”

“…For example, Wang et al 20 presented a statistical analysis of the available data of PM 2.5 in four residential dwellings with different building airtightness levels and Heating, Ventilation and Air Conditioning (HVAC)filter combinations, which revealed that the enhanced airtightness and the improvement of filter efficiency for both makeup air and indoor recirculated air decrease indoor PM 2.5 concentration significantly. Zhou et al 21 also proposed a method for controlling infiltration of PM 2.5 from outdoors and reducing indoor emissions, based on the experimental results of a typical residential building with different voids of windows and doors and different indoor emission sources. Waring et al 26 performed a two-phase investigation to evaluate the removal and generation of indoor pollution for two highefficiency particle arresting (HEPA) filters, one electrostatic precipitator with a fan, and two ion generators without fans, which showed that the pollutant removal benefits of ozone-generating air cleaners can be outweighed by the generation of indoor pollution, and portable HEPA filters were ultimately recommended.…”