Bladder cancer and arsenic through drinking water: a systematic review of epidemiologic evidence.

Exposure to inorganic arsenic (As) through drinking water is a major international public health issue. We carried out a systematic review of the existing literature examining the association between the risk of bladder cancer in humans and exposure to arsenic through drinking water. We searched electronic databases for studies published from January 2000 up to April 2013. Eight ecological studies, six case-control studies, four cohort studies and two meta-analyses were identified. The vast majority of the studies were carried out in areas with high arsenic concentrations in drinking water such as southwestern and northeastern Taiwan, Pakistan, Bangladesh, Argentina (Cordoba Province), USA (southeastern Michigan, Florida, Idaho) and Chile. Most of the studies reported higher risks of bladder cancer incidence or mortality in areas with high arsenic concentrations in drinking water compared to the general population or a low arsenic exposed control group. The quality assessment showed that among the studies identified, arsenic exposure was assessed at the individual level only in half of them and only three assessed exposure using a biomarker. Further, five out of eight ecological studies presented results with adjustment for potential confounders except for age; all cohort and case-control studies presented results with adjustment for cigarette smoking status in the analysis. The majority of the studies with varying study designs carried out in different areas provided evidence of statistically siginificant increases in bladder cancer risk at high concentrations of arsenic (>50 µg L(-1)). Assessing bladder cancer risk at lower exposure concentrations requires further investigation.

Bronchoalveolar lavage fluid cellular profile in workers exposed to chrysotile asbestos.

The cellular profile of bronchoalveolar lavage fluid (BALF) in asbestos-exposed population remains controversial. We, therefore, aimed to investigate BALF in apparently healthy individuals that were exposed in asbestos-related work for a long period of time. Participants were selected among employees of a car brakes and clutches factory that used chrysotile asbestos. Selection criteria were an employment history of ≥ 15 years and the absence of severe respiratory disease. The total number and type of BALF cells, the existence of dust cells, iron-laden macrophages and asbestos bodies were assessed. Thirty-nine workers (25 men), with a mean age of 46.2 ± 4.2 years and a mean employment time of 23.5 ± 4 years, participated. Asbestos bodies were observed in 14 out of 39 (36%) specimens, dust cells in 37 and iron-laden macrophages in all. Those with asbestos bodies had at least 3 times higher probability to have lymphocytosis (lymphocytes > 11%: 64% vs 28%, p = 0.027) and had an increased percentage of iron-laden macrophages compared to those without asbestos bodies (median values: 42% vs 13%, p = 0.08). Smokers (36%) had less lymphocytes compared to non and ex-smokers (median values: 6% vs. 13%, p = 0.002), and iron-laden macrophages count had a positive relation (r = 0.31, p = 0.05) to lymphocyte count. Asbestos-exposed asymptomatic individuals with the presence of asbestos bodies in the BALF are more likely to have lymphocytic alveolitis while concurrent dust exposure and smoking habits hold a significant role.