Occupational exposure to unintentionally emitted nanoscale particles and risk of cancer: From lung to central nervous system - Results from three French case-control studies

Relationship between Occupational Exposure to Airborne Nanoparticles, Nanoparticle Lung Burden and Lung Diseases

The biomonitoring of nanoparticles in patients’ broncho-alveolar lavages (BAL) could allow getting insights into the role of inhaled biopersistent nanoparticles in the etiology/development of some respiratory diseases. Our objective was to investigate the relationship between the biomonitoring of nanoparticles in BAL, interstitial lung diseases and occupational exposure to these particles released unintentionally. We analyzed data from a cohort of 100 patients suffering from lung diseases (NanoPI clinical trial, ClinicalTrials.gov Identifier: NCT02549248) and observed that most of the patients showed a high probability of exposure to airborne unintentionally released nanoparticles (>50%), suggesting a potential role of inhaled nanoparticles in lung physiopathology. Depending on the respiratory disease, the amount of patients likely exposed to unintentionally released nanoparticles was variable (e.g., from 88% for idiopathic pulmonary fibrosis to 54% for sarcoidosis). These findings are consistent with the previously performed mineralogical analyses of BAL samples that suggested (i) a role of titanium nanoparticles in idiopathic pulmonary fibrosis and (ii) a contribution of silica submicron particles to sarcoidosis. Further investigations are necessary to draw firm conclusions but these first results strengthen the array of presumptions on the contribution of some inhaled particles (from nano to submicron size) to some idiopathic lung diseases.

Development of a Job-Exposure Matrix for Ultrafine Particle Exposure: The MatPUF JEM

OBJECTIVE

Ultrafine particles (UFPs) are generated from common work processes and have thus existed for a long time. Far more prevalent than engineered nanoparticles, they share common toxicological characteristics with them. However, there is no existing retrospective assessment tool specific to UFPs, for example, for epidemiological purposes. Thus, we aimed to develop a job-exposure matrix dedicated to UFPs.

METHOD

Fifty-seven work processes were identified as well as the chemical composition of UFPs emitted, following a literature review and the input of an expert panel. These work processes were associated with occupational codes as defined by the ISCO 1968 classification. The probability and frequency of UFP exposure were assessed for each combination of occupational code and process. Summarized probabilities and frequencies were then calculated for all ISCO occupational codes associated with several processes. Variations in exposure over time or across industrial sectors were accounted for in the assessment of each occupational code.

RESULTS

In the ISCO classification, 52.8% of the occupational codes (n = 835) assessed were associated with exposure to UFPs, consisting mainly of carbonaceous, metallic, and mineral families (39.5%, 22 and, 15.8%, respectively). Among them, 42.6% involved very probable exposure, and at a high frequency (regularly or continuously).

CONCLUSION

These results suggest that occupational exposure to UFPs may be extensive at the workplace and could concern a wide variety of workers. Pending the integration of a third parameter assessing the intensity of UFP exposure, the MatPUF JEM already constitutes a promising and easy-to-use tool to study the possible adverse health effects of UFPs at work. It may also guide prevention policies in the occupational environments concerned, including those involving engineered nanoparticles.

Associations of age at natural menopause and occupations in Chinese female workers: A cross-sectional study

AIMS

To investigate the impact of occupation types on age at natural menopause.

METHODS

This is a nation-wide cross-sectional study based on 17,948 female workers aged over 40, who come from different industries or organizations. A face-to-face standardized questionnaire was conducted in all participants with the help of occupational hygienists. Occupational titles were coded according to the International Standard Classification of Occupations (2008) (ISCO08). Cox regression model was used to assess the association between each independent occupation and menopausal timing. Models were adjusted for marriage, education, average annual family income, parity, cigarette smoking, alcohol consumption.

RESULTS

Higher risks of earlier age at natural menopause was found among legislators and senior officials (ISCO Minor group:111, HR = 2.328, P < 0.001), among other health associated professionals (ISCO Minor group: 325, HR = 1.477, P = 0.003), the workers involved in mining and mineral processing (ISCO Minor group: 811, HR = 1.515, P = 0.048) and metal processing and finishing (ISCO Minor group: 812, HR = 1.722, P < 0.001). Reduced risks of earlier age at natural menopause, including: finance professionals (ISCO Minor group: 241, HR = 0.751, P = 0.021), manufacturing and construction supervisors (ISCO Minor group: 312, HR = 0.477, P = 0.002), administrative and specialized secretaries (ISCO Minor group: 334, HR = 0.788, P = 0.045), cleaners and helpers (ISCO Minor group: 911, HR = 0.633, P = 0.01).

CONCLUSIONS

This is the first study to address the influence of occupation types on reproductive aging, showing some specific occupations could be associated with age at natural menopause. Further investigations are necessary to clarify whether it is chance finding or a true association.