Cadmium Monitoring at the Workplace: Effectiveness of a Combination of Air- and Biomonitoring.

Inhalation exposure to cadmium at the workplace has been associated with an increased risk of lung cancer and non-cancer respiratory effects. To ensure levels of cadmium remain below effect levels, air quality is monitored and regulations specifying an air limit value are implemented. The EU Carcinogens and Mutagens Directive of 2019 recommended values for the inhalable fraction and the respirable fraction but the latter only for a transitional period. Cadmium exposure has also been associated with systemic effects, following its storage in the kidneys and due to its long half-life. The accumulation of cadmium occurs via different exposure routes and from different sources, including workplace dust and fumes, food, and smoking. Biomonitoring (in blood, urine) has been identified as the most appropriate method to follow up cumulative exposure and total cadmium body burden, as it conveniently reflects intakes by all routes. However, it is not systematically implemented. This paper has a double objective: first, proposing a possible limit value for the respirable fraction, using an approach integrating epidemiological data. Secondly, demonstrating that the implementation of both air and biological limit values is key to protecting workers' health in occupational settings. The paper summarizes the current knowledge on cadmium health effects and how biomarkers reflect those. It presents an approach to derive a respirable value, using recent human data, and describes how the combination of air monitoring and biomonitoring is applied by the EU industry to protect the workforce. While a respirable fraction value helps protect workers against local respiratory adverse health effects, air monitoring alone is not sufficient to protect workers against systemic effects of cadmium. Therefore, complementary biomonitoring and the implementation of a biological limit value is recommended.

Copper alloys' metal migration and bioaccessibility in saliva and gastric fluid.

The oral bioaccessibility of copper alloys and pure metals was assessed using in vitro methods with synthetic saliva and gastric fluid. The metal-specific migration rates from polished alloy surfaces are higher in gastric (pH 1.5) than in saliva fluid (pH 7.2). In both media, migrations are higher for lead than for other metals. The bioaccessible metal concentrations in massive copper alloys, after 2 h in gastric fluid, was only <0.01%-0.18%, consistent with the low surface reactivity of copper alloys (defined as 1 mm spheres). The average metal-specific migrations of cobalt, copper, nickel and lead from most of the tested copper alloys in gastric media are comparable to the ones from their pure metals. The data further show that the bioaccessibility of metals in massive copper alloys primarily depends on the bioelution medium, the exposed surface area and the composition of the alloy. The tested copper alloys show only limited evidence for influence of alloy surface microstructure. This is contrary to findings for other alloys such as stainless steel. Additional investigations on other copper alloys could allow to further refine these conclusions. These findings are useful for establishing the hazard and risk profile of copper alloys following oral exposure.