Silica exposure and disease in semi-precious stone craftsmen, Minas Gerais, Brazil.

BACKGROUND: Brazil is an exporter of precious stones and craftsmen often work in poor conditions. We assessed silica-related diseases among crystal craftsmen and the complexity of its control. METHODS: Case-series including 118 subjects evaluated from 2006 to 2015, based on medical interviews, chest X-rays, spirometry, and respirable silica samples. RESULTS: Median age and length of exposure were 32 and 13 years, respectively. Silicosis, with 1/0 as a threshold, was diagnosed radiologically in 57 individuals (48.3%). Respirable silica concentrations were 0.9-29.3 times greater than the Brazilian occupational exposure limit. A Receiver Operating Characteristic (ROC) curve with the same diagnosis threshold showed best discrimination at a cut point of 12.5 years of exposure, corresponding to 4.85 mg-y/m3 of cumulative silica exposure. There was a significant decline in FEV1 across radiological and cumulative silica exposure categories. Eleven individuals (9.3%) had mycobacterial diseases at baseline or follow-up. CONCLUSION: Crystal craftsmen continue to suffer from silicosis, lung function impairment, comorbidity, and death due to silicosis. To date collective protection in some work sheds has not diminished silica levels. Long-term follow-up is needed to evaluate further improvements in preventive measures. Am. J. Ind. Med. 60:239-247, 2017. © 2017 Wiley Periodicals, Inc.

Protective Effects of Quercetin on Livers from Mice Exposed to Long-Term Cigarette Smoke.

Cigarette smoke is highly toxic, and it can promote increased production of reactive species and inflammatory response and leads to liver diseases. Quercetin is a flavonoid that displays antioxidant and anti-inflammatory activities in liver diseases. This study aimed at evaluating the protective effects of quercetin on livers from mice exposed to long-term cigarette smoke exposure. Male C57BL/6 mice were divided into five groups: control (CG), vehicle (VG), quercetin (QG), cigarette smoke (CSG), quercetin, and cigarette smoke (QCSG). CSG and QCSG were exposed to cigarette smoke for sixty consecutive days; at the end of the exposures, all animals were euthanized. Mice that received quercetin daily and were exposed to cigarette smoke showed a reduced influx of inflammatory cells, oxidative stress, inflammatory reaction, and histopathological changes in the liver, compared to CSG. These results suggest that quercetin may be an effective adjuvant for treating damage to the liver due to cigarette smoke exposure.