Objective: Significantly lower permissible occupational exposure limits for copper dust are being discussed in Europe and other jurisdictions. However, little data are published on exposures in occupational settings and copperspecific effects in humans. Hence, a health surveillance study was performed among workers employed at a copper smelter between 1972 and 2018. Methods: Possible effects of long-term exposures to dust containing copper on lung function were assessed. Specifically, declines in forced expiratory volume in 1 second (FEV 1 ) were compared between a copper-exposed and control group. Cumulative copper exposures were derived from historical airborne monitoring data. Results: FEV 1 declines among exposed and control never smokers were similar to a typical age-dependent decline of 29 mL/y. Conclusion: The study findings indicate that cumulative inhalable copper dust exposure averaging 4.61 mg/m 3 -years over an exposure duration of $22 years is not associated with adverse effects on lung function.

Purpose Occupational exposure limits (OEL) for nitrogen oxides (NO, NO2) and diesel exhaust (EC-DPM) were reassessed by the German authorities in 2016/2017. We performed a clinical cross-sectional study among salt and potash underground workers exposed to these substances at relatively high levels to examine possible indicators of acute effects on workers’ health. Methods We measured post- versus pre-shift differences in cardiovascular, inflammatory, immune, and respiratory effect biomarkers and assessed their associations with personal exposures measured during the same shift. We also compared post- versus pre-shift differences in biomarker levels between exposure groups defined based on work site and job type. Results None of the above-ground workers exceeded the OEL for NO2 and only 5% exceeded the OEL for EC-DPM exposure. Among underground workers, 33% of miners and 7% underground maintenance workers exceeded the OEL for NO2; the OEL for EC-DPM was exceeded by 56% of miners and 17% of maintenance workers. Some effect biomarkers (thrombocytes, neutrophils, MPO, TNF-α, IgE, FeNO) showed statistically significant differences between pre- versus post-shift measurements; however, there were no consistent associations between pre- and post-shift differences and exposure group or personal exposure measurements during the shift. Conclusions We did not find evidence of associations between workplace exposure to NO, NO2 or EC-DPM and clinically relevant indicators of acute cardiovascular, inflammatory and immune, or respiratory effects among salt and potash underground workers in Germany.

The present cross-sectional study investigates whether biological relevant differences in lung function and inflammatory biomarkers exist between workers of a German copper plant and an internal comparison group. It complements a previously published historical health surveillance study and sheds light on possible subtle changes following long-term exposure to copper-containing dust.