Between a rock and a healthy place

Silicosis mortality among young adults in the United States, 1968-2004

BACKGROUND

To describe silicosis deaths in young (aged 15-44) adults in the U.S. during 1968-2004.

METHODS

We analyzed the National Center for Health Statistics multiple cause-of-death records.

RESULTS

Compared with silicosis decedents aged >or=45 years (n = 15,643), young decedents (n = 237) were more likely to have silicosis listed as the underlying cause of death (74.3% vs. 48.2%, P < 0.001), to be female (9.3% vs. 2.2%, P < 0.001) and black (37.1% vs. 11.7%, P < 0.001). Twenty-nine young silicosis decedents had industry and occupation information available. Occupations in construction and manufacturing industries were associated with significantly elevated proportionate mortality ratios for young silicosis deaths.

CONCLUSIONS

Silicosis deaths occur among young adults. Because these deaths are likely to reflect more intense and recent exposures, the follow-back investigations into the work sites where these individuals were exposed to silica should be conducted.

DNA damage in blood cells from children exposed to arsenic and lead in a mining area

In this work, we studied the frequency of DNA damage in children living in Villa de la Paz, Mexico, a mining site contaminated with arsenic and lead. DNA damage in blood cells was assessed using the Comet assay, and the results were compared to those found in children living in a less exposed town (Matehuala). In Villa de la Paz, high concentrations of arsenic and lead in surface soil and household dust were found. All of the soil samples had concentrations above 100 mg/kg of arsenic, and 58% of the samples were higher than 400 mg/kg of lead (these concentrations are used as intervention guidelines by the United States Environmental Protection Agency). In agreement with the environmental results, urinary arsenic in children living in Villa de la Paz (geometric mean 136 microg/g creatinine) was significantly higher than that found in children living in Matehuala (34 microg/g creatinine). Blood lead levels were also significantly higher in children from Villa de la Paz (11.6 microg/dL) than in children from Matehuala (8.3 microg/dL). The results of the Comet assay showed that the tail length and the tail moment in children living in Villa de la Paz were higher than those observed for children in Matehuala (P<0.05). Taking all the data into account, our study has shown increased DNA damage in children exposed to arsenic and lead in the mining site of Villa de la Paz.

Respiratory protection: associated factors and effectiveness of respirator use among underground coal miners

BACKGROUND

We investigated factors associated with the use of respiratory protection and explored the effectiveness of respirators among coal miners.

METHODS

Between 1987 and 1992, respiratory symptoms, smoking, lung function, and dust exposures were assessed longitudinally among 185 underground bituminous coal miners. Self-reported use of respiratory protection was expressed as mean percent time wearing a respirator.

RESULTS

Miners' respirator use increased with mean dust concentration, but decreased with tobacco consumption. Increasing age was associated with greater respirator use. Miners who had respiratory symptoms at the initial survey subsequently reported greater use of respirators. A significant protective association was found between the miners' respirator use and FEV(1) levels at both the initial and follow-up surveys.

CONCLUSIONS

These results provide additional evidence that respirator use is protective of lung health. When respiratory protection programs are developed, factors that may affect respirator use behavior, such as age, smoking, and respiratory symptoms, should be considered. Future studies of respiratory health will need to consider workers' use of respiratory protection.