IAP studies from India and China
Dan Campbell
Activation of protein kinase B (PKB/Akt) and risk of lung cancer among rural women in India
JANUARY 12, 2012 · 0 COMMENTS
Toxicol Appl Pharmacol. 2011 Dec 8.
Activation of protein kinase B (PKB/Akt) and risk of lung cancer among rural women in India who cook with biomass fuel.
Roychoudhury S, Mondal NK, Mukherjee S, Dutta A, Siddique S, Ray MR.
The impact of indoor air pollution (IAP) from biomass fuel burning on the risk of carcinogenesis in the airways has been investigated in 187 pre-menopausal women (median age 34years) from eastern India who cooked exclusively with biomass and 155 age-matched control women from same locality who cooked with cleaner fuel liquefied petroleum gas. Compared with control, Papanicolau-stained sputum samples showed 3-times higher prevalence of metaplasia and 7-times higher prevalence of dysplasia in airway epithelial cell (AEC) of biomass users. Immunocytochemistry showed up-regulation of phosphorylated Akt (p-Akt(ser473) and p-Akt(thr308)) proteins in AEC of biomass users, especially in metaplastic and dysplastic cells.
Compared with LPG users, biomass-using women showed marked rise in reactive oxygen species (ROS) generation and depletion of antioxidant enzyme, superoxide dismutase (SOD) indicating oxidative stress. There were 2-5 times more particulate pollutants (PM(10) and PM(2.5)), 72% more nitrogen dioxide and 4-times more particulate-laden benzo(a)pyrene, but no change in sulfur dioxide in indoor air of biomass-using households, and high performance liquid chromatography estimated 6-fold rise in the concentration of benzene metabolite trans,trans-muconic acid (t,t-MA) in urine of biomass users.
Metaplasia and dysplasia, p-Akt expression and ROS generation were positively associated with PM and t,t-MA levels. It appears that cumulative exposure to biomass smoke increases the risk of lung carcinogenesis via oxidative stress-mediated activation of Akt signal transduction pathway.
Patterns and predictors of personal exposure to indoor air pollution from biomass combustion
JANUARY 12, 2012 · 0 COMMENTS
Indoor Air. 2011 Dec;21(6):479-88.
Patterns and predictors of personal exposure to indoor air pollution from biomass combustion among women and children in rural China.
Baumgartner J, Schauer JJ, Ezzati M, Lu L, Cheng C, Patz J, Bautista LE.
Institute on the Environment, University of Minnesota, St. Paul, MN 55108, USA. jbaumg...@umn.edu
Indoor air pollution (IAP) from domestic biomass combustion is an important health risk factor, yet direct measurements of personal IAP exposure are scarce. We measured 24-h integrated gravimetric exposure to particles < 2.5 μm in aerodynamic diameter (particulate matter, PM₂.₅) in 280 adult women and 240 children in rural Yunnan, China. We also measured indoor PM₂.₅ concentrations in a random sample of 44 kitchens. The geometric mean winter PM₂.₅ exposure among adult women was twice that of summer exposure [117 μg/m³ (95% CI: 107, 128) vs. 55 μg/m³ (95% CI: 49, 62)].
Children’s geometric mean exposure in summer was 53 μg/m³ (95% CI: 46, 61). Indoor PM₂.₅ concentrations were moderately correlated with women’s personal exposure (r=0.58), but not for children. Ventilation during cooking, cookstove maintenance, and kitchen structure were significant predictors of personal PM₂.₅ exposure among women primarily cooking with biomass. These findings can be used to develop exposure assessment models for future epidemiologic research and inform interventions and policies aimed at reducing IAP exposure.
PRACTICAL IMPLICATIONS: Our results suggest that reducing overall PM pollution exposure in this population may be best achieved by reducing winter exposure. Behavioral interventions such as increasing ventilation during cooking or encouraging stove cleaning and maintenance may help achieve these reductions.