Background

ATSDR’s Cooperative Agreement Program provides 30 states and tribes with training and technical assistance to provide the best response to the public when chemical exposures become dangerous.

This partnership showed its strength in Idaho this spring when EPA called on the Idaho Dept. of Health and Welfare Bureau of Community and Environmental Health (BCEH) and ATSDR assistance to rapidly assess the dangers of a gas leak and make quick recommendations to protect the health of workers at a toxic waste site.

The Eastern Michaud Flats area of southeastern Idaho, on the Fort Hall Indian Reservation, was home to a phosphorous production plant from 1949 to 2001. Earlier this year, the EPA investigated gas leaks from the site after learning that FMC Corporation, the Philadelphia-based chemical corporation that operated the plant, had detected phosphine gas concentrations at dangerous levels.

Addressing the Problem

After analyzing air data from the phosphine gas leaks, BCEH learned that gas levels escaping a capped pond area reached levels above recommended limits and sometimes higher than meters could record. If levels high enough above the meters’ measurement were reached, breathing the air for just a few seconds without protective gear could cause severe health effects or death.

Upon learning this, the BCEH released a Health Consultation on June 2 declaring the site an urgent public health hazard – ATSDR’s strongest category of hazard -- meaning short-term exposures from breathing the air close to the pond could cause adverse health effects and rapid response is needed. The gas was not only a hazard to workers cleaning up the site, but also to any visitors and trespassers in the pond area.

ATSDR and BCEH are working closely with EPA, FMC, and the Shoshone-Bannock tribes to ensure appropriate public health actions are taken and recommended the following immediate steps to protect public health:

• Adequate fencing, a more robust fence line monitoring program, and signage to keep people out and warn them of the dangers of phosphine gas
• Consultating with OSHA to ensure that the site’s health and safety plan complies with all applicable OSHA standards and that the respiratory protection program conforms to NIOSH recommendations
• Assessment of new monitoring data as they become available with findings reported to EPA and development of an ongoing sampling plan
• Educating local emergency personnel about the potential risks on-site

Results

On June 14, EPA ordered FMC to address phosphine gas releases at multiple ponds at the site. Under the order, FMC must control the release or threat of release of phosphine gas from the ponds to the surrounding air and conduct sampling to evaluate performance and ensure protection of human health and the environment. EPA, BCEH, and the Shoshone-Bannock tribes have begun reviewing FMC’s proposed sampling plan. FMC has installed a temporary gas extraction and treatment system and, according to EPA, phosphine levels decreased significantly after its installation. FMC also revised its contingency plan this month and provided copies to emergency responders who have been invited to tour the site at the end of June. BCEH plans to continue working with EPA to assess new monitoring data and complete a follow-up health consultation.

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