Systematic evidence mapping for updating health reference values: A case example using acrolein
On this page:
Transparent, methodologically rigorous, and rapid approaches are needed for updating human health assessments. Evidence mapping is a potentially helpful type of systematic review analysis, especially when combined with machine-learning software advances. In a case study with acrolein, we evaluated the applicability of evidence mapping to determine whether new evidence may result in a change to an existing health reference value. In addition, the evidence map was designed to identify studies that might not be suitable for reference value derivation but could be important to consider for hazard characterization or to identify emerging areas that should be explored in future research. Over 13,000 studies were identified, and 40 studies were considered relevant after full-text review. Most of these studies were short-term exposure animal studies and not considered suitable for deriving a chronic reference value. The epidemiology studies identified had limitations in exposure assessment or ability to use the exposure metric to derive an inhalation value. After considering the relevant studies identified from the evidence map, the 2008 subchronic rat study used by Cal EPA OEHHA for their reference value derivation appear to still be the most appropriate study for chronic reference value derivation for acrolein. Additionally, we identified new advances in dosimetric modeling for gases, including new evidence pertinent to acrolein, which could be considered for updating existing acrolein toxicity values. Further details from this analysis will be presented. In conclusion, evidence mapping appears to be a useful and efficient tool for human health risk assessment.