Air pollution affects health, but much of the focus to this point has been on outdoor air. Higher indoor pollution is anticipated due to increasingly energy-efficient and less leaky buildings together with more indoor activities. Studies of indoor air pollution focusing on children and people with respiratory disease from the database Web of Science (1991–2021) were systemically reviewed according to the PRISMA guidelines, with 69 studies included in the final selection. Emissions from building materials affected indoor air quality, and ventilation also had an influence. The main indoor air pollutants are Volatile Organic Compounds (VOCs) and Particulate Matter (PM). PM sources included smoking, cooking, heating, candles, and insecticides, whereas sources of coarse particles were pets, housework and human movements. VOC sources included household products, cleaning agents, glue, personal care products, building materials and vehicle emissions. Formaldehyde levels were particularly high in new houses. Personal exposure related to both indoor and outdoor pollutant levels, highlighting home characteristics and air exchange rates as important factors. Temperature, humidity, educational level, air purifiers and time near sources were also related to personal exposure. There was an association between PM and Fractional exhaled Nitric Oxide (FeNO), lung function, oxygen saturation, childhood asthma and symptoms of chronic obstructive pulmonary disease (COPD) patients. High VOCs were associated with upper airways and asthma symptoms and cancer. Effective interventional studies for PM in the future might focus on human behavior together with air purifiers and increased ventilation, whereas VOC interventions might center more on building materials and household products, alongside purification and ventilation.

Background and aim: Patient related outcomes are important in sarcoidosis, but the medium-term repeatability of the key patient reported outcome measure is not known. We aimed to test the repeatability of the Fatigue Assessment Scale (FAS), Short Form 6-Dimension (SF-6D), and King's Sarcoidosis Questionnaire (KSQ) in free living people with sarcoidosis associated fatigue. Methods: Twelve people with sarcoidosis associated fatigue completed the FAS, short form 36 questionnaire (SF-36) and the KSQ at baseline and 12 weeks. The SF-6D utility was calculated from the SF-36. The difference between baseline and 12 week assessments was measured. Results: The interclass correlation (95% confidence interval) showed good agreement between the baseline and 3 months measurements: FAS 0.91 (0.74, 0.71), SF-36 0.98 (0.94, 1), KSQ 0.98 (0.93, 0.99), SF-6D utility 0.98 (0.93, 0.99). The baseline (standard deviation) FAS was 27.83 (5.86) and at 12 weeks was 27.25 (7.55) representing a 0.58 difference (95% CI for difference (-1.89, 3.06)), SF-6D utility was 0.69 (0.16) at baseline and 0.68 (0.17) after 3 months representing at 0.00 (-0.03, 0.03) difference and corresponding values for KSQ were 59.12 (18.68) and 56.91 (27.26) with a difference of-1.87 (5.49,1.76). Conclusions: There was good repeatability of FAS, SF-36, SF-6D and KSQ in free living people with sarcoidosis associated fatigue. Fatigue, general and disease specific health related quality of life showed no significant change over 12 weeks. Studies identifying changes in these outcomes can confidently report a true change and not measurement error or regression to the mean.