title: Providing perspective for interpreting cardiovascular mortality risks associated with ozone exposures.
abstract: When identifying standards for air pollutants based on uncertain evidence, both science and policy judgments play critical roles. Consequently, critical contextual factors are important for understanding the strengths, limitations, and appropriate interpretation of available science, and potential benefits of risk mitigation alternatives. These factors include the relative magnitude and certainty of the risks posed by various factors and the impacts of other risk factors on air pollutant epidemiology study findings. This commentary explores ozone's status as a risk factor for cardiovascular mortality in contrast with decades of strong and consistent evidence for other established risk factors. By comparison, the ozone evidence is less conclusive, more heterogeneous, and subject to substantial uncertainty; ozone's potential effects, if any, are small and challenging to discern. Moreover, the absence of a demonstrated causal relationship calls into question efforts to quantify cardiovascular mortality risks attributed to ozone exposures on a population level and highlights the need to explicitly acknowledge this uncertainty if such calculations are performed. These concerns are relevant for other similar policy contexts - where multiple established risk factors contribute to the health impact of interest; exposure-effect associations are relatively small, weak, and uncertain; and a causal relationship has not been clearly established.
authors.affiliation: Gradient, 600 Stewart Street, Ste 1900, Seattle, WA 98101, USA. Electronic address: cpetitoboyce@gradientcorp.com.
authors.forename: Catherine
authors.initials: C
authors.lastname: Petito Boyce
authors.affiliation: Gradient, 20 University Road, Ste 5, Cambridge, MA 02138, USA. Electronic address: jgoodman@gradientcorp.com.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Goodman
authors.affiliation: Gradient, 20 University Road, Ste 5, Cambridge, MA 02138, USA. Electronic address: ssax@gradientcorp.com.
authors.forename: Sonja N
authors.initials: SN
authors.lastname: Sax
authors.affiliation: Gradient, 600 Stewart Street, Ste 1900, Seattle, WA 98101, USA. Electronic address: cloftus@gradientcorp.com.
authors.forename: Christine T
authors.initials: CT
authors.lastname: Loftus
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects; D002318:Cardiovascular Diseases / Q000139:chemically induced* / Q000401:mortality*; D002319:Cardiovascular System / Q000187:drug effects*; D004781:Environmental Exposure / Q000009:adverse effects*; D006801:Humans; D010126:Ozone / Q000009:adverse effects*; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D000393:Air Pollutants; D010126:Ozone
keywords: Air pollution; Cardiovascular mortality; Environmental health policy; NAAQS (National Ambient Air Quality Standards); Ozone exposure