The EPA announced Risk Assessment Procedures for Hazardous Air Pollutants from Stationary Sources on 23 August 2019. These regulations provide environmental competent authorities with consistent procedures for conducting health risk assessments, when amending or formulating the emissions standards for hazardous air pollutants (HAPs). These procedures will help the EPA with its work on reducing risk of exposure to HAPs so as to protect the public’s health.
The announced procedures are in accordance with the Air Pollutant Control Act, amended on 1 August 2018, which states that stationary pollution source emission standards must include HAPs. Such standard values shall be based on the results of health risk assessments and the feasibility of prevention measures. The categories of the above-mentioned HAPs and the health risk assessment procedures shall be announced by central competent authorities. Setting standardized health risk assessment procedures will provide a valuable reference for environmental competent authorities.
The procedures base their scope on the categories of the HAPs announced by the EPA and assess the impacts to human health of inhalation exposure. They must be conducted according to the following:
(1) Identification of hazards: The categories of toxicity (e.g. carcinogenicity, prenatal developmental toxicity, reproductive toxicity, developmental toxicity, mutagenicity, systemic toxicity), emission sources, and amounts emitted must be assessed.
(2) Dose-effect assessment: For carcinogenic HAPs, inhalation cancer slope factor or inhalation unit risk shall be determined, while for non-carcinogenic HAPs, reference concentration (both acute and chronic) shall be assessed.
(3) Exposure assessment: The total inhalation exposure to the spread of HAPs among residents living in the affected areas of the regulated entities shall be assessed.
(4) Description of risk characteristics: Based on the results of the above assessments, the total increased carcinogenic and non-carcinogenic risks caused by the regulated HAPs for residents living in the affected areas of the regulated entities shall be assessed. Risk assessments shall be analyzed for uncertainty with a 95% upper confidence limit.
Excerpt from Environmental Policy Monthly, 22 (9)
- Environmental Protection Administration, R.O.C.(Taiwan)