Governor Chris Christie • Lt.Governor Kim Guadagno
NJ Home | Services A to Z | Departments/Agencies | FAQs  
State of New Jersey-Department of Environmental Protection-Bureau of Stationary Sources
State of New Jersey Department of Environmental Protection
DEP Home | BoSS Home | About DEP | Index by Topic | Programs/Units | DEP Online 
Risk Screening Tools

Estimating Risk from Air Toxics

 Technical Manual 1003: Guidance on Preparing a Risk Assessment Protocol for Air Contaminant Emissions

 Procedures to Conduct Risk Assessments to Determine the Incremental Health Risks from New or Modified Equipment

Description Format Updated

Cancer Risk Screening Worksheet for Nonroad Diesel Engines

Development of the Risk Screening Worksheet for Nonroad Diesel Engines

MS Excel Microsoft Excel Spreadsheet


Adobe Pdf Adobe Acrobat Pdf Reader




Revisions to the NJDEP/DAQ Risk Screening Worksheet Adobe Pdf Adobe Acrobat Pdf Reader 8/11
NJDEP Division of Air Quality Risk Screening Worksheet for Long-Term Carcinogenic and Noncarcinogenic Effects and Short-Term Effects MS Excel Microsoft Excel Spreadsheet 2/14
Methodology and Assumptions Used to Generate the Revised Level-1 Air Impact Values Adobe Pdf Adobe Acrobat Pdf Reader 4/07
Risk Screening Policy and Second-Level Risk Screening Adobe Pdf Adobe Acrobat Pdf Reader 6/07
Toxicity Values for Inhalation Exposure Adobe Pdf Adobe Acrobat Pdf Reader 8/11
Risk Screening for PAH/POM Adobe Pdf Adobe Acrobat Pdf Reader 1/13

General Information on Health Effects of Air Toxics

Air toxics can be broadly grouped into two categories according to their health effects: carcinogens (cancer-causing) or noncarcinogens. Carcinogens are those chemicals that have been shown to cause cancer, either in people or animals. Noncarcinogens have other kinds of health effects, affecting such things as development, reproduction, respiration, the liver, kidney or other organs. Health effects of chemicals are discovered in a number of ways. Researchers can study groups of people that have been exposed to the chemicals in the past, usually at the workplace. They can also expose volunteers to specific amounts of a chemical and record the effects. Most health effects information comes from studies of animals that are exposed in the laboratory to specific doses of a chemical for specific periods of time.

Using Health Benchmarks

Groups of experts at government agencies, such as USEPA and California EPA, look at all of the studies done on the health effects of a chemical, and recommend measures of toxicity, known as unit risk factors and reference concentrations, that can be used to evaluate public exposure to those chemicals.

Unit risk factors are measures used for carcinogens that estimate the increased risk of getting cancer associated with the concentration of the chemical in the air that you are breathing. A risk of less than one in a million is considered to be negligible.

Reference concentrations are measures developed for noncarcinogens. Exposure to a chemical below the reference concentration, even over a long period of time, is not expected to have any negative effect on health.

These unit risk factors and reference concentrations can be used as health benchmarks, to evaluate the potential health effects of air toxic concentrations. For carcinogens, the health benchmark is the air concentration that would result in a one in a million increase in the risk of getting cancer if a person inhaled that concentration over a whole lifetime. For noncarcinogens, health benchmarks are set at the reference concentration. Air concentrations that are below these health benchmarks are not expected to be harmful to human health. It is not always clear, however, how far above the health benchmark an air concentration has to be before it becomes harmful. Types of harmful health effects and actual harmful levels will vary substantially from pollutant to pollutant.