Abstract

When families live and work in the same environment, respirable silica places all family members at high risk for developing chronic non-communicable respiratory diseases. Individuals exposed to silica are one of only a few high-risk groups that the World Health Organisation (WHO) recognises as being at substantial risk and in need of population-based screening for TB. According to the National Institute for Occupational Safety and Health (NIOSH), the association between TB and silicosis has been firmly established. Increased risk of TB has been repeatedly demonstrated in surveillance, case-control, and cohort studies from around the world. When compared with the general population, estimates of increased risk range from just over 2-fold to almost 40-fold, and increased risk of extra-pulmonary TB is almost 4-fold greater.

The failure to place a greater emphasis on occupational health in dusty trades may be a lost opportunity of enormous magnitude. While limited, data from several nations indicate that pneumoconioses are a large and persistent problem. We were not able to find any data on the risk of silica exposure to young workers or children living in silica-contaminated environments. However, work in dusty occupations, such as brick making, and living and working in a brick-kiln environment are common to children. The risk of silicosis increases with increased intensity and/or duration of exposure, and chronic silicosis may develop or progress even after exposure to silica has ended. Hence, it is important to understand the impacts of both childhood and cumulative lifetime exposure.

Although there are few studies of brick-kiln workers, both historic and recent data indicate that silica exposure is a problem. For example, in mechanised South African brickyards among workers with <10 years of service, the prevalence of silicosis was 1%, 4.5%, and 8.6% for those whose exposures had been rated as low, medium, and high, respectively. There was radiographic evidence of TB in 9.3% of workers. There are approximately 1200 brick kilns in Nepal and 1,40,000 in India employing an estimated 2 50 000 and 9 million workers, respectively. Between 10% and 30% of workers are <16 years old, although estimates vary greatly. The number of individuals living at the kiln itself is likely to be many orders of magnitude higher. In addition to work-related exposure, parents are compelled to bring their children and infants to the workplace due to a lack of childcare, thereby resulting in high dust exposures to this especially vulnerable population.