Table 1

Studies included in the meta-analysis investigating the association between biomass fuel use and respiratory outcomes in women or children in rural settings

Author	Country	Study design	Fuel used	Stove type	Exposure	Subjects	Sample size	Diagnosis	Respiratory outcome	OR	95% CI
Akhtar et al27	Pakistan	Case–control	Biomass	U-shaped stove, triangularly shaped stove and metallic angithi	11–20 years of cooking and up to 4 h of cooking per day	Women 10–60+ years Mean age 30.96±10.65 years	1426 exposed 1131 controls	Self-reported	Chronic bronchitis	2.51	1.65 to 3.83
Behera et al16	India	Cross-sectional	Biomass	Chulla stove	NA	Children 7–15 years	200	Self-reported	ARI	2.98	0.74 to 11.99
								Self-reported	Asthma	0.16	0.01 to 3.24
								Self-reported	Bronchitis	0.32	0.03 to 3.18
Behera et al34	India	Cross-sectional	Biomass	NA	Cases: 69.0±44.2 h-year Controls: 54.1±31.8 h-year of cooking	Women mean age 37.2±8.8 years	50 exposed 50 controls	Clinically confirmed, spirometry	Asthma	1.52	0.62 to 3.75
Collings et al28	Zimbabwe	Case–control	Wood	Open wood fire	Mean concentration of PM 1998±1915 μg/m³ in lower respiratory disease cases 546±666 μg/m³ in upper respiratory disease cases	Children 1 month–3 years	244 cases 500 controls	Clinically confirmed	ARI	2.16	1.44 to 3.26
Dennis et al29	Colombia	Case–control	Wood	NA	Cases: 32.8±16 mean years of wood use Controls: 18±14 years	Women 35–70+ years mean age Cases: 63.08±10 years Controls: 62.04±11 years	104 cases 104 controls	Clinically confirmed	COPD	3.92	1.70 to 9.10
Ehrlich et al35	South Africa	Cross-sectional	Wood, coal, dung	NA	NA	Women 15–65+ years	8073	Self-reported, Spirometry	Chronic bronchitis	1.50	1.00 to 2.10
Ekici et al36	Turkey	Cross-sectional	Wood, grass, crop, dung	Biomass stove	131.1±96.6 h-year of cooking	Women 40+	397 exposed 199 controls	Clinically confirmed	COPD	1.40	1.20 to 1.70
Fagbule et al17	Nigeria	Case control	Biomass	NA	NA	Children mean 66 months	140 cases 140 controls	Clinically confirmed	Asthma	0.15	0.07 to 0.30
Golshan et al37	Iran	Cross-sectional	Wood, crop residue	Tandoor stove	PM10 concentrations on three random days and three postbaking days Kitchen 4080±730 ppb of PM₁₀; 5970±590 ppb of total PM Sitting room after wood combustion for baking 2910±470 ppb of PM₁₀; 4310±680 ppb of total PM Sitting room on random days 1220±480 ppb of PM10; 1900±880 of total PM	Women 1 month–81 years Mean 27.62±16.6 years	561	Clinically confirmed	Asthma	1.08	1.01 to 1.27
Golshan et al37	Iran	Cross-sectional	Wood, crop residue	Tandoor stove				Clinically confirmed	Chronic bronchitis	2.91	2.08 to 4.40
Kilabuko et al38	Tanzania	Cross-sectional	Wood	Tandir stove	PM₁₀, NO₂, CO concentrations in kitchen, living room and outdoors	Women	77 exposed	Self-reported	ARI	5.50	3.60 to 8.50
Kilabuko et al38	Tanzania	Cross-sectional	Wood	Tandir stove		Children <5 years	73 exposed	Reported by parents	ARI	7.98	4.63 to 13.78
Kiraz et al39	Turkey	Cross-sectional	Dung, woodsticks	Traditional stove	NA	Women 25+ Exposed: 40.5±15.05 years Controls: 43.62 ±11.94 years	242 exposed 102 controls	Clinically confirmed	Chronic bronchitis	3.19	1.39 to 7.32
Kiraz et al39	Turkey	Cross-sectional	Dung, woodsticks	Traditional stove	NA			Clinically confirmed	COPD	11.12	1.48 to 83.34
Liu et al40	China	Cross-sectional	Wood, crop residue	Chulla stove	PM₁₀, SO₂, NO₂, CO concentrations during cooking in the kitchen, living room and outdoors	Women 40+ years	1089	Self-reported, spirometry	COPD	3.11	1.63 to 5.94
Malik et al41	India	Cross-sectional	Cowdung cakes, firewood	Open fire, stove without flue	NA	Women 20+ years	2180	Clinically confirmed, spirometry	Chronic bronchitis	3.28	1.39 to 7.76
Melsom et al30	Nepal	Case control	Wood, grass	U-shaped chulha stove	NA	Children 11–17 years	121 cases 126 controls	Self-reported	Asthma	2.20	1.00 to 4.50
Mishra et al45	India	Cross-sectional	Wood, dung	NA	NA	Children <3 years	33 875	Reported by parents	ARI	1.32	0.91 to 1.92
Mishra et al42	India	Cross-sectional	Wood, straw, dung	unvented stove	NA	Women 60+ years	18 117	Self-reported	Asthma	1.83	1.32 to 2.53
Mishra et al42	Zimbabwe	Cross-sectional	Wood, straw, dung	NA	NA	Children 0–59 months	3559	Reported by parents	ARI	2.20	1.16 to 4.19
Mishra et al44	India	Cross-sectional	Wood, straw, dung	NA	NA	Children <36 months	29 768	Reported by parents	ARI	1.58	1.28 to 1.95
Morris et al31	USA	Case control	Wood	Wood stove	NA	Children ≤24 months	58 cases 58 controls	Clinically confirmed	ALRI	4.85	1.69 to 12.91
Noorhassim et al18	Malaysia	Cross-sectional	Wood	Three-stone open fire	NA	Children 1–12 years	1007	Clinically confirmed	Asthma	0.62	0.30 to 1.29
Qureshi et al19	India	Case–control	Firewood	Chulha stove	2–4 mean h/day spent near fireplace	Women 15+ years	131 cases 138 controls	Clinically confirmed	Asthma	0.79	0.17 to 3.58
Savitha et al32	India	Case–control	Firewood, dung	Three-stone fires, plancha stove	NA	Children 1 month–5 years	104 cases 104 controls	Clinically confirmed	ALRI	32.63	13.61 to 72.25
Sezer et al33	Turkey	Case–control	Dung	Clay stove	At least 2–4 h a day for 10 years	Women Cases: 57.08±11.10 years Controls: 56.35 ±10.78 years	74 cases 74 controls	Clinically confirmed	COPD	1.66	0.89 to 3.10
Shrestha et al46	Nepal	Cross-sectional	Wood, crop residue, dung	Traditional stove	Kitchen PM₁₀ 2418.07 μg/m³	Women 36.1±16.7 years	158	Clinically confirmed	ALRI	2.77	0.77 to 10.00
								Clinically confirmed	COPD	3.13	0.83 to 11.76
Uzun et al47	Turkey	Cross-sectional	Wood	Wood-burning stove	1–20+ years	Women 17–75 years mean 41±12 years	90 exposed 87 controls	Clinically confirmed	Asthma	1.47	0.24 to 8.99
								Clinically confirmed	Chronic bronchitis	3.46	1.85 to 6.45

ARI, acute respiratory infection; ALRI, acute lower respiratory infection; CO, carbon monoxide; COPD, chronic obstructive lung disease; NA, data not available; NO₂, nitrogen dioxide; PM, particulate matter; PM₁₀, particulate matter with aerodynamic diameter 10 μm.