Inflammation, oxidative stress, and higher expression levels of Nrf2 and NQO1 proteins in the airways of women chronically exposed to biomass fuel smoke.

The study was carried out to examine whether chronic exposure to smoke during daily household cooking with biomass fuel (BMF) elicits changes in airway cytology and expressions of Nrf2 (nuclear factor erythroid 2 [NF-E2]-related factor 2 [Nrf2]), Keap1 (Kelch-like erythroid-cell-derived protein with CNC homology [ECH]-associated protein 1), and NQO1 (NAD(P)H:quinone oxidoreductase 1) proteins in the airways. For this, 282 BMF-using women (median age 34 year) and 236 age-matched women who cooked with liquefied petroleum gas (LPG) were enrolled. Particulate matter with diameters of < 10 µm (PM10) and < 2.5 µm (PM2.5) were measured in indoor air with real-time laser photometer. Routine hematology, sputum cytology, Nrf2, Keap1, NQO1, and generation of reactive oxygen species (ROS) along with the levels of superoxide dismutase (SOD) and catalase were measured in both groups. PM10 and PM2.5 levels were significantly higher in BMF-using households compared to LPG. Compared with LPG users, BMF users had 32% more leukocytes in circulation and their sputa were 1.4-times more cellular with significant increase in absolute number of neutrophils, lymphocytes, eosinophils, and alveolar macrophages, suggesting airway inflammation. ROS generation was 1.5-times higher in blood neutrophils and 34% higher in sputum cells of BMF users while erythrocyte SOD was 31% lower and plasma catalase was relatively unchanged, suggesting oxidative stress. In BMF users, Keap1 expression was reduced, the percentage of AEC with nuclear expression of Nrf2 was two- to three-times more, and NQO1 level in sputum cell lysate was two-times higher than that of LPG users. In conclusion, cooking with BMF was associated with Nrf2 activation and elevated NQO1 protein level in the airways. The changes may be adaptive cellular response to counteract biomass smoke-elicited oxidative stress and inflammation-related tissue injury in the airways.

Changes in RANKL and osteoprotegerin expression after chronic exposure to indoor air pollution as a result of cooking with biomass fuel.

The impact of indoor air pollution as a result of cooking with unprocessed biomass on membrane-bound and serum receptor activator of nuclear factor-kappa ligand 1 (RANKL), its soluble decoy receptor osteoprotegerin (OPG) and osteoclast precursor CD14(+) CD16(+) monocytes was investigated. Seventy-four pre-menopausal women from eastern India using biomass and 65 control women who cooked with cleaner liquefied petroleum gas were enrolled. PM10 and PM2.5 levels in their indoor air were measured with real-time aerosol monitors. The levels of membrane-bound RANKL on leukocytes and percentage CD14(+) CD16(+) monocytes in the subjects' blood were assayed by flow cytometry. Soluble RANKL and OPG in serum were measured by ELISA. The results showed that PM10 and PM2.5 levels were significantly higher in the indoor air of biomass-using households. Compared with the control women, the levels of CD4(+) and CD19(+) lymphocytes and circulating granulocytes with elevated levels of membrane-bound RANKL were higher in biomass users. The serum levels of RANKL were increased by 41% whereas serum OPG was reduced by 22% among biomass users. The absolute number of CD14(+) CD16(+) monocytes was significantly increased in biomass users than the control women. After controlling for potential confounders, PM10 and PM2.5 levels were found to be positively associated with leukocyte and serum RANKL and CD14(+) CD16(+) monocyte levels, but negatively with serum OPG. From these results, we can conclude that chronic exposure to biomass smoke increased membrane-bound and soluble RANKL and circulating osteoclast precursors but decreased OPG, suggesting an increased risk of bone resorption and consequent osteoporosis in biomass-exposed women of a child-bearing age. Copyright © 2015 John Wiley & Sons, Ltd.

Platelet hyperactivity, neurobehavioral symptoms and depression among Indian women chronically exposed to low level of arsenic.

The prevalence of neurobehavioral symptoms (NBS) and depression has been investigated in premenopausal rural women of West Bengal, India enrolled from arsenic (As) endemic (groundwater As 11-50 µg/L; n = 342) and control areas (As level ≤ 10 µg/L; n = 312). The subjective symptoms questionnaire and Beck's 21-point depression inventory-II were used for the detection of NBS and depression, respectively. Platelet P-selectin expression was measured by flow cytometry, plasma neurotransmitter activity with high performance liquid chromatography and groundwater As level by atomic absorption spectroscopy. The As level in groundwater was 2.72 ± 1.18 µg/L in control and 28.3 ± 13.51 µg/L in endemic areas (p < 0.0001). Women residing in endemic areas demonstrated a higher prevalence of depressive symptoms (39.8 vs. 19.9%, p < 0.001) and anxiety (43.3 vs. 18.0% in control, p < 0.001), fatigue (68.4 vs. 23.4%, p < 0.0001), reduced sense of taste (15.8 vs. 4.5%, p<0.0001) and smell (14.9 vs. 5.8%, p < 0.001); burning sensation (36.8 vs. 5.4%, p < 0.0001) and tingling or numbness in the extremities (25.1 vs. 5.1%, p < 0.0001); and transient loss of memory (69.9 vs. 28.2%, p < 0.001). As-exposed women had 1.6-times more plasma epinephrine and norepinephrine (p < 0.05), 1.8-times higher level plasma serotonin with 28.9% lower intraplatelet serotonin (p < 0.05 for both), but their plasma dopamine level was not significantly different (p>0.05) from that of controls. Moreover, women from endemic areas had 2.3-times more P-selectin-expressing platelets in their circulation (p < 0.001). After controlling the potential confounders, chronic low level As (11-50 µg/L) exposure showed a positive association with the prevalence of neurobehavioral symptoms and depression among Indian women in their child-bearing age.

Increased oxidative DNA damage and decreased expression of base excision repair proteins in airway epithelial cells of women who cook with biomass fuels.

To investigate whether biomass burning causes oxidative DNA damage and alters the expression of DNA base excision repair (BER) proteins in airway cells, sputum samples were collected from 80 premenopausal rural biomass-users and 70 age-matched control women who cooked with liquefied petroleum gas. Compared with control the airway cells of biomass-users showed increased DNA damage in alkaline comet assay. Biomass-users showed higher percentage of cells expressing oxidative DNA damage marker 8-oxoguanine and lower percentages of BER proteins OGG1 and APE1 by immunocytochemical staining. Reactive oxygen species (ROS) generation was doubled and level of superoxide dismutase was depleted significantly among biomass-users. The concentrations of particulate matters were higher in biomass-using households which positively correlated with ROS generation and negatively with BER proteins expressions. ROS generation was positively correlated with 8-oxoguanine and negatively with BER proteins suggesting cooking with biomass is a risk for genotoxicity among rural women in their child-bearing age.

Chronic low-level arsenic exposure reduces lung function in male population without skin lesions.

OBJECTIVES: The respiratory effects of chronic low-level arsenic exposure from groundwater have been investigated in West Bengal, India. METHODS: The participants (834 non-smoking adult males) were subdivided in two groups: an arsenic-exposed group (n = 446, mean age 35.3 years) drinking arsenic-contaminated groundwater (11-50 µg/L) and a control group of 388 age-matched men drinking water containing <10 µg/L of arsenic. Arsenic in water samples was measured by atomic absorption spectroscopy. The prevalence of respiratory symptoms was documented by structured, validated questionnaire. Pulmonary function test (PFT) was assessed by portable spirometer. RESULTS: Compared with control, the arsenic-exposed subjects had higher prevalence of upper and lower respiratory symptoms, dyspnea, asthma, eye irritation and headache. Besides, 20.6% of arsenic-exposed subjects had lung function deficits (predominantly restrictive and combined types) compared with 13.6% of control (p < 0.05). A positive association was observed between arsenic concentration in drinking water and the prevalence of respiratory symptoms, while a negative association existed between arsenic level and spirometric parameters. CONCLUSIONS: The findings suggest that even low-level arsenic exposure has deleterious respiratory effects.