Health Risk Assessment
A risk assessment, as defined under the Air Toxics Hot Spots Act, includes a comprehensive analysis of the dispersion of hazardous substances into the environment, the potential for human exposure, and a quantitative assessment of both individual and population-wide health risks associated with those levels of exposure. Assembly Bill (AB) 2588 (Connelly), the Air Toxics Hot Spots Information and Assessment Act, requires high priority facilities to submit a health risk assessment (HRA) to the air pollution control and air quality management districts (district) for approval. The district may require facilities in the intermediate and low priority categories to also submit a health risk assessment. The Office of Environmental Health Hazard Assessment (OEHHA) reviews the risk assessments prior to district approval.
CARB's Health Analyses
CARB worked with Union Pacific (UP) and BNSF to complete an HRA to evaluate associated health impacts of toxic air contaminants emitted from 17 major railyards in California.
CARB completed an HRA to study the emissions impacts and the potential public health risk from exposures to diesel particulate matter (PM). The sources of diesel PM included activities at the Maritime Port of Oakland, the UP Railyard, and other sources in and near the West Oakland community of the Bay Area.
Preliminary Health Analyses
To support new regulatory developments, CARB completed health analyses to examine the health benefits gained by implementing new proposed regulatory requirements for ocean going vessels and transport refrigeration units. The preliminary health analyses are presented below:
- Preliminary Health Analyses for Ocean Going Vessels
- Preliminary Health Analyses for Transport Refrigeration Units
OEHHA HRA Guidelines
OEHHA is the lead state agency for the assessment of health risks posed by environmental contaminants. Senate Bill 1731, which amends the Hot Spots Program, requires OEHHA to adopt risk assessment guidelines for the program using a full public review process. OEHHA released the final version of the document, Air Toxics Hot Spots Program Guidance Manual for the Preparation of Risk Assessments, February 2015. See responses to frequently asked questions related to the OEHHA guidelines.
Hotspots Analysis and Reporting Program
The Hotspots Analysis and Reporting Program (HARP) is a tool that assists with the programmatic requirements of the Air Toxics Hot Spots Program. HARP is a single integrated software package that can be used by the air pollution control and air quality management districts (districts), facility operators, and other parties to promote statewide consistency, efficiency, and cost-effective development of facility and emission inventories and health risk assessments. HARP can also be used for other types of health risk assessments used in other programs (e.g., facility permitting).
Risk Management Policy for Risk Assessment Using the Inhalation Pathway
This policy is presented in Appendix D of the document CARB/CAPCOA Risk Management Guidance for Stationary Sources of Air Toxics (July 23, 2015). CARB and the California Air Pollution Control Officers Association's (CAPCOA) established this policy through a public process with input from industry and environmental representatives. This policy uses the new risk assessment science included in the OEHHA Guidance Manual while providing a reasonable estimate of potential cancer risk for use in risk assessments for risk management decisions. The individual Districts have the authority to decide how, or if, they will use this recommended policy in their programs.
See workshops and meetings related to the implementation of the Risk Management Guidance for Stationary Sources of Air Toxics.
Consolidated Table of OEHHA/CARB Approved Risk Assessment Health Values
The Consolidated Table of OEHHA/CARB Approved Risk Assessment Health Values is a quick look-up table of all cancer potency values and noncancer acute and chronic Reference Exposure Levels (RELs) that are available for use in the AB 2588 Air Toxics Hot Spots Program. This table includes cancer potency values and noncancer RELs that have been approved by OEHHA and CARB or are listed in CAPCOA's Risk Assessment Guidelines (1993). OEHHA is currently in the process of developing new risk assessment guidelines that will update and replace the CAPCOA guidelines.
Review of Updated and Screening HRAs
In 1997, the staff of CARB, OEHHA, and the Districts collaborated to develop a streamlined process for the submittal and review of updated, and screening, HRAs. That joint effort resulted in the development of a set of forms intended to accompany the submittal of updated, or screening, HRAs to the appropriate district and to OEHHA. There is also a list of the minimum data fields required when submitting an updated, or screening, HRA for those individuals that chose to not use the forms developed.
Industrywide Risk Assessments
CAPCOA, in cooperation with OEHHA and the CARB, developed three industry-wide risk assessment procedures. The purpose of these industry specific assessments is to assist both the districts and facilities with the emission inventory and risk assessment requirements of the Air Toxics Hot Spots Program.
The three industrial sectors covered by the industry-wide assessments are: auto bodyshops, gasoline service stations, and dry cleaners. Facilities which meet a specific set of requirements outlined in the law are candidates for an industry-wide assessment. The requirements are focused on small businesses that are from the same industrial class, where individual compliance would impose severe economic hardships, and where emissions are easily and generically characterized.
Please refer to the list below to download a copy of a particular risk assessment guideline.