The effect of exposure to biomass smoke on respiratory symptoms in adult rural and urban Nepalese populations.
BACKGROUND
Half of the world's population is exposed to household air pollution from biomass burning. This study aimed to assess the relationship between respiratory symptoms and biomass smoke exposure in rural and urban Nepal.


METHODS
A cross-sectional study of adults (16+ years) in a rural population (n = 846) exposed to biomass smoke and a non-exposed urban population (n = 802) in Nepal. A validated questionnaire was used along with measures of indoor air quality (PM2.5 and CO) and outdoor PM2.5.


RESULTS
Both men and women exposed to biomass smoke reported more respiratory symptoms compared to those exposed to clean fuel. Women exposed to biomass were more likely to complain of ever wheeze (32.0 % vs. 23.5%; p = 0.004) and breathlessness (17.8% vs. 12.0%, p = 0.017) compared to males with tobacco smoking being a major risk factor. Chronic cough was similar in both the biomass and non-biomass smoke exposed groups whereas chronic phlegm was reported less frequently by participants exposed to biomass smoke. Higher PM2.5 levels (≥2 SDs of the 24-hour mean) were associated with breathlessness (OR = 2.10, 95% CI 1.47, 2.99) and wheeze (1.76, 1.37, 2.26).


CONCLUSIONS
The study suggests that while those exposed to biomass smoke had higher prevalence of respiratory symptoms, urban dwellers (who were exposed to higher ambient air pollution) were more at risk of having productive cough.
Om P
OP
Kurmi
Sean
S
Semple
Graham S
GS
Devereux
Santosh
S
Gaihre
Institute of Occupational and Environmental Medicine, University of Birmingham, Birmingham B15 2TT, UK. k.lam@bham.ac.uk.
Kin Bong Hubert
KB
Lam
Steven
S
Sadhra
Markus F C
MF
Steiner
Padam
P
Simkhada
William C S
WC
Smith
Jon G
JG
Ayres
D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D018533:Biomass; D003371:Cough / Q000139:chemically induced / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000139:chemically induced / Q000453:epidemiology; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009390:Nepal / Q000453:epidemiology; D015995:Prevalence; D012135:Respiratory Sounds / Q000209:etiology; D012307:Risk Factors; D012424:Rural Population; D012906:Smoke / Q000009:adverse effects*; D014505:Urban Population; D055815:Young Adult
D000393:Air Pollutants; D012906:Smoke