Table 1 Study characteristics of studies with non-occupational populations
From: Respiratory health effects of exposure to low levels of airborne endotoxin – a systematic review
Non-occupational populations | ||||||||
|---|---|---|---|---|---|---|---|---|
Author (Year) Country | Study designa | Population | Ageb | Endotoxin assessment methods | Exposure variables measured | Spirometry | Questionnaire | Confounders accounted for |
Asthma/COPD patient populations | ||||||||
Rabinovitch et al. (2005) US [45] | CS | 24 asthmatic school-children | 8.8–9.0 (SD 1.0–1.1) | -Personal and stationary sampling -37 mm Teflon filter - 2 L/min -LAL assay | Airborne endotoxin, PM | FEV1 | Questionnaire on asthma severity | – |
Delfino et al. (2015) US [46] | L: follow up 10 days | 43 asthmatic school-children | 14.3 (range 9–18) | -Personal sampling (10 days) - 2.5 μm cyclone filter -4 L/min -LAL assay | PM2.5, endotoxin | FEV1 and FeNO | Reporting the use of asthma medication and symptoms every two waking hours | Temperature, humidity |
Lai et al. (2015) US [47] | L: follow up 12 months | 248 asthmatic school-children | 8 (range 4–13) | -Area air sampling with charged particle samplers (Quadra) -LAL assay | Airborne endotoxin, settled dust and settled endotoxin | FEV1 and FVC | Questionnaire on respiratory symptoms and follow-up phone calls | Age, sex, race, annual income, controller medication, home and school settled dust endotoxin and mouse allergen, season |
Bose et al. (2016) US [62] | L: follow up 6 months | 84 COPD patients | 68.9 (SD 7.4) | -Area air sampling -37-mm Teflon filters -4 L/min -LAL assay | Airborne and dust endotoxin, PM, second hand smoke, NO2 | FEV1 | Combination of MRC dyspnoea scale, modified ATS-DLD, and St. George’s Respiratory Questionnaire | Age, gender, education, season of sampling, baseline pre-bronchodilator percent predicted FEV1 |
Other non-occupational populations | ||||||||
Schiffman et al. (2005) US [35] | E: 1 h expo-sure | 48 healthy subjects | 26 (±9.46) | - Air sampling -Fiberglass filters -46 L/min -LAL assay | H2S, ammonia, total suspended particles, endotoxin and odour | FVC, FEV1and FEF25–75% | Environmental Exposures and Health Questionnaire | Subjects were their own controls. |
Hoopmann et al. (2006) Germany [37] | CS | 3867 children | Range: 5–6 | Individual exposure estimated with Lagrange dispersion model based on the emission of neighbouring livestock facilitiesc | Airborne endotoxin, fungi, bacteria, total dust | – | Questionnaire of the ISAAC studies for respiratory and allergic symptoms | Atopic status parents |
Horick et al. (2006) US [38] | L: follow up 12 months | 360 children | range 2–3 months | Airborne endotoxin levels were calculated from dust endotoxin levelsd | Endotoxin, dust | – | Monthly telephone calls during the first year of the child’s life | Race, pets, total mass of dust collected, concrete floor, water damage and respiratory illness |
Ramagopal et al. (2014) US [61] | CS | 75 children | Range: 3–59 months | Method 1: Stationary Indoor Monitors (SIM) Method 2: PIPER (pre-toddler inhalable particulate environmental robotic) | PM, endotoxin | – | ISAAC questionnaire | Age, gender, family history of asthma, floor covering, pets |