Environmental Health Tools – CAMEO and AEGLs

As a public service, Impact Analysis: Adventures in Environmental Health will present, from time to time, tools for environmental health analysis.

After 9-11, the federal government took down numerous web sites providing useful information for assessing natural and man-made hazards, including offsite consequence analysis (OCA) data from Risk Management Plans (RMPs) for chemical facilities, formerly made available by the U.S. Environmental Protection Agency (EPA).

There is a dilemma between addressing a community’s right to know about the hazards from the ton cylinders of chlorine gas at the nearby wastewater treatment plant, and keeping information about how to create terrible clouds of toxic chemicals out of the hands of dangerous people. While the bias for secrecy may reduce risks of chemical terrorism, it has fostered a dangerous complacency on the part of the general public, who ultimately provide the oversight on authorities and facility operators handling hazardous chemicals. Not enough has been done to address the risks to communities from extremely hazardous substances.

However, for those willing to learn, the tools are available for developing hazard assessments. While not a replacement for the formerly publicly accessible information on extremely hazardous substances in your community, these tools can provide some increased understanding of those hazards and what your role can be in helping managing them.

CAMEO

CAMEO is a set of three computer programs – CAMEO, MARPLOT and ALOHA used to help community officials and first responders plan for chemical emergencies. CAMEO is a database of information on health and explosive hazards, firefighting and other protective measures for thousands of chemicals. MARPLOT is mapping software that can display sensitive receptors, response assets, roads, etc., and can also overlay contaminant plume from chemical releases onto these terrain features. ALOHA – Areal Location of Hazardous Atmospheres is an air dispersion model that can estimate concentrations in air from a hazardous chemical release.

CAMEO can be paired up with Acute Exposure Guideline Levels (AEGLs). AEGLs describe the human health risks resulting from short-term exposure to airborne chemicals.

AEGLs

Developed by a national advisory committee funded by the U.S. Environmental Protection Agency (EPA) and the Agency for Toxic Substances and Disease Registry (ATSDR), AEGLs were developed to help both federal and local authorities, as well as private companies, deal with emergencies involving spills, or other accidental exposures. A standard operating procedure (SOP) for calculating AEGLs is available from the National Academy Press. The AEGLs and supporting documentation are also published by NAP, though the values are available from EPA’s web site.

How these values work is:

The AEGL-1 concentration in air may result in detectable odor, or produce some noticeable symptoms, such as eye or respiratory irritation (sore throat, cough) or a headache. The “effects are not disabling” means that these exposures should not affect your ability to escape and move to fresh air. The symptoms should cease after moving to fresh air.

Exposure to the AEGL-2 concentration in air over the specified time period (30 minutes, 1 hour, etc.) may produce long-lasting or irreversible health effects, usually effects to the lungs or nervous system. Exposure may also affect your ability to escape (this is used for planning purposes for telling paramedics and firefighters just how long they have to evacuate people from an impacted area)

Exposure to the AEGL-3 concentration in air over the specified time period could be life-threatening – this tells the paramedics and firefighters that they should be evacuating those areas first. It also tells them to approach those areas in air-supplied respirators.

So, get started – there are plenty of examples of generic facilities in EPA’s RMP guidance to work with. It’s not the actual RMPs, but with that information and what you can find in the EPA’s Toxic Release Inventory (TRI), you can get some idea of the nature of chemicals hazards in your community.

What you can do about them to protect yourself – that’s for another day.