NCHR’s Comment on the Draft IRIS Assessment Plan and Protocol for Assessing Cancer Risk from Inhalation Exposure to Cobalt and Cobalt Compounds

December 14, 2022 

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We are pleased to have the opportunity to share our views with the Environmental Protection Agency (EPA) on the Draft IRIS Assessment Plan (IAP) and Protocol for Assessing Cancer Risk from Inhalation Exposure to Cobalt and Cobalt Compounds. 

The National Center for Health Research (NCHR) is a nonprofit think tank that conducts, analyzes, and scrutinizes research on a range of health issues, with particular focus on which prevention strategies and treatments are most effective for which patients and consumers. We do not accept funding from companies that make products that are the subject of our work, so we have no conflicts of interest. 

NCHR supports the EPA’s decision to explore the dose-response and risk of developing cancer from cobalt and cobalt compound exposure via inhalation. Many other health organizations, including the National Institute for Occupational Safety and Health (NIOSH) and the Center for Disease Control (CDC), recognize that cobalt is a likely human carcinogen based on animal studies showing that inhalation of these compounds can cause cancer.1,2 It is important for the EPA to investigate if the same link extends to humans as well. 

An analysis of the growing body of evidence is needed to better understand the upper-dose limit and how to prevent dangerous exposures through the use of respiratory masks or other strategies. This will enable the CDC and Occupational Safety and Health Administration (OSHA) to create guidelines and requirements that the industry must follow to protect worker’s health. However, we urge the EPA to consider how possible health risks from inhaling cobalt may differ among various subpopulations. We also encourage the EPA to investigate further the impact of cobalt inhalation on children of various ages and if it causes birth defects in humans similar to those seen in animal studies.2 If certain subpopulations are determined to have a higher likelihood of cobalt exposure that surpasses their permissible dose limit, or greater vulnerability to harm caused by exposure, we strongly urge the EPA to develop requirements to ensure that their health is protected. 

 

 

References: 

1. The National Institute for Occupational Safety and Health. Cobalt. cdc.gov. https://www.cdc.gov/niosh/topics/cobalt/default.html Updated June 24, 2019. 

2. Agency for Toxic Substances and Disease Registry. ToxFAQs for Cobalt. Cdc.gov. https://wwwn.cdc.gov/TSP/ToxFAQs/ToxFAQsDetails.aspx?faqid=372&toxid=64