Agriculture & Biology
air quality
100%
biogas
88%
households
76%
human health
75%
carbon monoxide
47%
particulates
39%
cooking stoves
36%
indoor air pollution
35%
gases
30%
risk reduction
25%
longitudinal studies
24%
charcoal
22%
combustion
21%
petroleum
19%
biofuels
19%
death
15%
Earth & Environmental Sciences
indoor air quality
96%
biogas
79%
household
67%
human health
66%
digester
44%
carbon monoxide
40%
exposure
35%
particulate matter
34%
health
28%
indoor air pollution
27%
charcoal
20%
gas
20%
effect
19%
petroleum
15%
combustion
15%
biomass
12%
world
11%
need
10%
comparison
8%
Engineering & Materials Science
Biogas
93%
Carbon monoxide
89%
Air quality
89%
Indoor air pollution
66%
Health
59%
Charcoal
56%
Gases
46%
Wood
37%
Biomass
36%
Crude oil
35%