The Warren Township and LaBrae School District requested that ATSDR evaluate hydrogen sulfide exposure for residents in Warren Township near the Warren Recycling Center and determine whether the data indicate contamination levels of health concern. These are the conclusions and recommendations from the ATSDR health consultation concluded in September 2002.

Conclusions

1. Assuming the air monitoring data is accurate, ATSDR concludes that hydrogen sulfide in air currently presents a public health hazard to area residents and school children. Furthermore, health effects reported through numerous interviews with residents are consistent with hydrogen sulfide exposure. Adverse health effects could result from chronic exposure to measured hydrogen sulfide levels in ambient air. Hydrogen sulfide exposure is of particular concern for residents with pre-existing health conditions (such as asthma or respiratory problems), and sensitive populations such as children and the elderly. In addition, hydrogen sulfide is an olfactory (smell) depressant and flammable gas at higher levels, which could cause a dangerous situation if gases accumulate in an unvented area of a house or other building, such as a basement.
2. Because ambient and indoor air concentrations of hydrogen sulfide have not been fully characterized, it is not known whether the levels reported represent average exposure scenarios. Air data have a number of limitations, and warrant additional sampling.
3. The odors in indoor air have not been characterized. Residential reports of odors emanating from residential water well supplies could indicate natural sulfur deposits in underground aquifers, but may also indicate landfill gas is migrating through the soil into area residential basements.
4. Levels of hydrogen sulfide on and in the landfill may pose a threat of fire and/or explosion.

Recommendations

1. Install and maintain hydrogen sulfide alarms in each of the three elementary and high schools in the area. Each school should develop a contingency plan with local emergency responders to determine appropriate protective measures needed during high release periods.
2. Monitor residential indoor and ambient air for a more representative (e.g., seasonal) period of time to ensure peak and average hydrogen sulfide levels are determined . Proper QA/QC procedures should be incorporated and utilized to create a valid and accurate data set.
3. Sample private wells used by residences near the facility to ensure that hydrogen sulfide (or other gases) are not present at levels of health concern.
4. Screen indoor residential air during well sampling to determine if levels of hydrogen sulfide or other combustible gases are present at hazardous levels.
5. Install and intermittently sample groundwater monitoring wells at the perimeter of the site hydraulically up and downgradient to evaluate whether leachate is impacting aquifers used for drinking water by area residents.
6. Identify all major sources for hydrogen sulfide in ambient air. Local and state officials should continue to work to reduce exposure of area residents to hydrogen sulfide gas, and to ensure that facilities identified as sources comply with these strategies to protect the health of the public.