EPA refers to Cumulative Risk Assessment(CRA) as the analysis, characterization, and possible quantification of combined risks to health or the environment posed by multiple agents or stressors. As the name implies CRA looks at the sum of risks associated with various stressors not just the individual compound of interest. It seems very complicated and is just starting to be used.
The concept has got us thinking about the training we do for workers exposed to lead, silica, VOCs , etc. It seems like a good idea to inform the workers about other stressors that exist that may enhance the effect of an exposure. Things such as existing medical conditions, other chemical exposures that may occur during or outside work, or situations that may be causing higher than normal stress levels create concerns about disproportional risk burdens. When a worker is exposed to a contaminant that contaminant does not act independently. Many factors contribute to the worker experiencing an effect. For example if a worker is exposed to lead and has an underlying condition such as hypertension then that worker may be at higher risk than a healthy worker with the same lead exposure.The impact would not be detected by a blood lead test but it would still exist.
Hazard Communication should not be limited to a discussion about the effects of an exposure in a vacuum. Training should be more holistic and discuss other things that may effect the worker's health. The added CRA component to all training should be designed to inform the worker about the cumulative risk associated with other stressors in their lives so that they, as individuals, can look at their own situation and decide if their risk may be higher than normal due to their individual circumstances. These are factors that industrial hygiene professionals have not typically considered.
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