Application of an indoor air pollution metamodel to a spatially-distributed housing stock

Abstract

Estimates of population air pollution exposure typically rely on the outdoor component only, and rarely account for populations spending the majority of their time indoors. Housing is an important modifier of air pollution exposure due to outdoor pollution infiltrating indoors, and the removal of indoor-sourced pollution through active or passive ventilation. Here, we describe the application of an indoor air pollution modelling tool to a spatially distributed housing stock model for England and Wales, developed from Energy Performance Certificate (EPC) data and containing information for approximately 11.5 million dwellings. First, we estimate indoor/outdoor (I/O) ratios and total indoor concentrations of outdoor air pollution for PM 2.5 and NO 2 for all EPC dwellings in London. The potential to estimate concentration from both indoor and outdoor sources is then demonstrated by modelling indoor background CO levels for England and Wales pre- and post-energy efficient adaptation, including heating, cooking, and smoking as internal sources. In London, we predict a median I/O ratio of 0.60 (99% CIs; 0.53–0.73) for outdoor PM 2.5 and 0.41 (99%CIs; 0.34–0.59) for outdoor NO 2 ; Pearson correlation analysis indicates a greater spatial modification of PM 2.5 exposure by housing (ρ = 0.81) than NO 2 (ρ = 0.88). For the demonstrative CO model, concentrations ranged from 0.4–9.9 ppm (99%CIs)(median = 3.0 ppm) in kitchens and 0.3–25.6 ppm (median = 6.4 ppm) in living rooms. Clusters of elevated indoor concentration are found in urban areas due to higher outdoor concentrations and smaller dwellings with reduced ventilation potential, with an estimated 17.6% increase in the number of living rooms and 63% increase in the number of kitchens exceeding recommended exposure levels following retrofit without additional ventilation. The model has the potential to rapidly calculate indoor pollution exposure across large housing stocks and estimate changes to exposure under different pollution or housing policy scenarios.

Setting the standard: The acceptability of kitchen ventilation for the English housing stock

“…The value of P depends on the size distribution of the aerosol and the flow characteristics through an airflow path [42], where P = 1 for airflow through large openings, such as open windows, and P < 1 for other airflow paths [30]. P has been found to vary between 0.7 and 0.9 with particle size [30], but previous models have treated PM 2.5 as an homogeneous pollutant and modelled P = 0.8 for the heating season conditions [43] considered here. Therefore, P is considered uniformly distributed between 0.7 and 0.9.…”

“…The ambient, or external, PM 2.5 concentration is assumed to be uniformly distributed between 8.6 µg/m 3 and 14.6 µg/m 3 . These concentrations are reported for London [43], however there is a precedent of applying this data to the entire housing stock [23].…”

Volatile Organic Compounds (VOCs) Removal from Indoor Air by Heterostructures/Composites/Doped Photocatalysts: A Mini-Review

“…There are various categories of indoor air pollutants: CO x , NO x , small particles, volatile organic compounds (VOCs), etc. [ 1 , 2 , 3 ]. Among them, VOCs can reach ten times higher concentrations indoors than outdoors, as a consequence of emissions from electronics, building materials and consumer goods [ 4 , 5 , 6 ].…”

Enhancing the Photocatalytic Activity of SnO2-TiO2 and ZnO-TiO2 Tandem Structures Toward Indoor Air Decontamination

“…Another important aspect is represented by indoor air pollution is the fact that many people usually live and work in closed spaces (Zhou et al, 2017). Acetaldehyde is a subject of interest for researchers analyzing indoor pollution (Amoatey et al, 2018;Chen et al, 2020), as it can be released for long periods by different construction materials such as polyurethane foams, adhesives, coatings, inks, and consumer products like cigarettes (Wang et al, 2016;Lin et al, 2017;Taylor et al, 2019). Direct contact with acetaldehyde irritates the skin and eyes, while short term inhalation affects the human respiratory system.…”