Physico-chemical properties of quartz from industrial manufacturing and its cytotoxic effects on alveolar macrophages: The case of green sand mould casting for iron production

Cumulative occupational exposure to inorganic dust and fumes and invasive pneumococcal disease with pneumonia

PURPOSE

Occupational exposure to inorganic dust and fumes in the year preceding disease has been associated with increased pneumococcal pneumonia risk, but the impact of prior cumulative exposure has not been characterized.

METHODS

We studied 3184 cases of invasive pneumococcal disease with pneumonia. The case index date was the day the infection was diagnosed. We selected six controls for each case from the Swedish population registry; each control was assigned the index date of their corresponding case. We linked job histories to a job-exposure matrix to calculate a cumulative exposure index, intensity-years, by multiplying the duration (maximum 5 years) of each exposure with the level of exposure (0 for unexposed, 1 for low and 4 for high). We used conditional logistic analyses to estimate the odds ratio (OR) of invasive pneumococcal disease with pneumonia adjusted for comorbidities, educational level, income and other occupational exposures.

RESULTS

Taking other occupational exposures into account, greater than 5 intensity-years of exposure to silica dust or to fumes was each associated with increased odds for invasive pneumococcal disease with pneumonia (OR 2.53, 95% CI 1.49-4.32) and (OR 2.24, 95% CI 1.41-3.55), respectively. Five intensity-years or less of exposure to silica dust or fumes manifested lower odds (OR 1.45, 95% CI 1.20-1.76) and (OR 1.05, 95% CI 0.94-1.16), respectively.

CONCLUSION

This study adds evidence that the risk of pneumococcal pneumonia increases with increasing cumulative exposure to dust and fumes, indicating the importance of cumulative exposure.

Occupational exposure to dust and to fumes, work as a welder and invasive pneumococcal disease risk

Objectives

Occupational exposures to metal fumes have been associated with increased pneumonia risk, but the risk of invasive pneumococcal disease (IPD) has not been characterised previously.

Methods

We studied 4438 cases aged 20–65 from a Swedish registry of invasive infection caused by Streptococcus pneumoniae. The case index date was the date the infection was diagnosed. Six controls for each case, matched for gender, age and region of residency, were selected from the Swedish population registry. Each control was assigned the index date of their corresponding case to define the study observation period. We linked cases and controls to the Swedish registries for socioeconomic status (SES), occupational history and hospital discharge. We applied a job–exposure matrix to characterise occupational exposures. We used conditional logistic analyses, adjusted for comorbidities and SES, to estimate the OR of IPD and the subgroup pneumonia–IPD, associated with selected occupations and exposures in the year preceding the index date.

Results

Welders manifested increased risk of IPD (OR 2.99, 95% CI 2.09 to 4.30). Occupational exposures to fumes and silica dust were associated with elevated odds of IPD (OR 1.11, 95% CI 1.01 to 1.21 and OR 1.33, 95% CI 1.11 to 1.58, respectively). Risk associated with IPD with pneumonia followed a similar pattern with the highest occupational odds observed among welders and among silica dust exposed.

Conclusion

Work specifically as a welder, but also occupational exposures more broadly, increase the odds for IPD. Welders, and potentially others with relevant exposures, should be offered pneumococcal vaccination.

Determination of crystalline silica in respirable dust upon occupational exposure for Egyptian workers

Crystalline free silica is considered as a lung carcinogen and the occupational exposure to its dust is a health hazard to workers employed in industries that involve ores of mineral dust. In Egypt, thousands of people work under conditions of silica dust exposure exceeding the occupational exposure limit, as a result the monitoring of this occupational exposure to crystalline silica dust is required by government legislation. The assessment of the later is a multi-phase process, depend on workplace measurements, quantitative analyses of samples, and comparison of results with the permissible limits. This study aims to investigate occupational exposure to crystalline silica dust at 22 factories in Egypt with different industrial activities like stone cutting, glass making, ceramic, and sand blasting. Dust samples were collected from work sites at the breathing zone using a personal sampling pump and a size-selective cyclone and analyzed using FTIR. The sampling period was 60-120 min. The results show that the exposure at each of the industrial sectors is very much higher than the current national and international limits, and that lead to a great risk of lung cancer and mortality to workers.