The observed elevated risk among women exposed to silica is not surprising in view of its
classification by the International Agency for Research on Cancer (IARC) as a confirmed
(category 1) human lung carcinogen.28 Excessive lung cancer risks have been noted
consistently in many silica-exposed occupations,29 although to our knowledge, this is the
first such report from the textile industry. Silica exposure in the Shanghai textile industry
occurred almost exclusively in the foundries where textile machines were made and
repaired. Although a relatively small number of women workers were exposed to silica, its
hazardous potential deserves attention in the textile industry. However, any conclusions
about a carcinogenic risk from silica in this cohort should be made with some caution
because we could not assess exposures to carcinogenic polycyclic aromatic hydrocarbons
that also occur in foundries.30 Confounding by asbestos is very unlikely, as we did not
identify any jobs held by women workers with potential exposures.