State and federal officials confirmed Friday that tests showed toxic chemical presence of hundreds of thousands of times the accepted upper safe exposure levels for humans in south Fulton County beginning in late spring and early summer.

“Based on results from environmental sampling, preliminary analysis of reported symptoms and the scientific data on the behavior of the chemicals involved, propyl mercaptan was released into the air at the PSC plant in late June and most likely caused symptoms reported in the community,” according to DPH Director Stuart Brown and EPD Director Carol Couch.

The strong onion-like odor noticed by thousands of people in a 40-square-mile “hot zone” around a waste pre-treatment plant south of Fairburn was present at the plant at levels far beyond recommended safe exposure levels, officials revealed.

Tests results released Friday showed the onion-like odor emanating from the Philip Services Corp. (PSC) waste treatment plant on Spence Road inside Fulton County during the summer contained 640,000 times the recommended human exposure level to the chemical odorant propyl mercaptan.

The chemical was a component of the “pesticide wash water” shipments that entered plant property in big sealed barrels on a tractor-trailer truck in late June and were returned to the shipper in Alabama as unacceptable.

The Sept. 15 report by Georgia Division of Public Health (DPH) and Georgia Environmental Protection Division (EPD) showed enormous levels of the chemical odorant propyl mercaptan and organophosphate pesticide MOCAP in test samples taken Aug. 27 by the federal Environmental Protection Agency at the AMVAC chemical plant in Axis, Ala. AMVAC was the origin of the chemicals later refused at the PSC plant.

Exposure limits for propyl mercaptan are .5 parts per million (ppm) with a recommended ceiling of 15 minutes, according to National Institute for Occupational Safety and Health (NIOSH).

The quantity of propyl mercaptan documented in the EPD sampling tests revealed 320,000 milligrams per kilogram (mg/kg), equal to 320,000 ppm, or 640,000 times the recommended exposure limit.

While tests cannot confirm the exact amount of the chemicals encountered in neighborhoods in north Fayette and south Fulton, the symptoms reported by more than 750 residents in those areas conform to the inhalation symptoms listed on Material Safety Data Sheets.

Those symptoms include difficulty breathing, headache, nausea, diarrhea, kidney damage, lung congestion, irritation, vomiting, symptoms of drunkenness, lack of sense of smell, bluish skin color, convulsions and coma.

The level of MOCAP (known chemically as ethoprop) found in the sample was enormous, found to be 240,000 ppm. Unlike the MOCAP found in the sample, which Stuart and Couch said did not readily evaporate and would likely not have caused a serious health problem, propyl mercaptan does evaporate quickly in the environment.

The Sept. 15 letter noted that the laboratory analysis does not necessarily represent the exact chemical composition of the waste as it existed at the PSC facility because the railcar in Alabama may have contained residues from previous contents, the possibility of chemical reactions that might have occurred in the tank over the nine-week period after the pesticide water wash returned to the AMVAC facility and due to other materials being added to the waste in an attempt to deodorize the waste.

Still unaccounted for are the numerous reports by area residents that the same onion-like odor was present in their neighborhoods since Memorial Day.

Many residents reported the same symptoms during the period from late May through the June 29 date when the four shipments of MOCAP water wash arrived at PSC and were rejected.

Local, state and federal officials have been investigating the chemical release since the story was first revealed in The Citizen.

The PSC plant is state-licensed as a waste pre-treatment plant, which handles both solid and liquid wastes before disposing of the treated materials in landfills or into the Fulton County sewer system.

However, the state EPD has admitted that it can find no records for any shipments at the PSC plant covering the past 16 years, despite regulatory requirements that the agency receive yearly reports on exactly what kinds of wastes are being brought to the PSC plant.

Following is the official report from the Georgia Department of Public Health and the state Environmental Protection Division released Sept. 15:

Re: Update: Sampling Results

The Georgia Environmental Protection Division (EPD) has completed laboratory analysis of two samples of waste taken from a railcar at the AMVAC chemical plant in Axis, Alabama.

Representatives of the U.S. Environmental Protection Agency (EPA) took the railcar samples on Aug. 27, 2006.

According to AMVAC, the railcar contained four 5,000-gallon truckloads of pesticide wash water, which were returned by the PSC Recovery Systems pre-treatment wastewater facility in Fairburn, Ga.

The laboratory analysis does not necessarily represent the exact chemical composition of the waste as it existed at the PSC facility for several reasons:

• The railcar used to store the waste may have contained residues from its previous contents.

• Additional materials were added to the waste in an attempt to deodorize the waste.

• Chemical reactions may have taken place in the tank over time.

However, the EPD analysis does offer information regarding the chemical composition of the highly malodorous waste, which has been blamed for numerous health complaints in the area surrounding the PSC facility.

The waste in the railcar at the AMVAC facility in Alabama consists of two distinct layers, an upper layer that is an organic liquid (like oil) and a lower layer that is an aqueous liquid (like water). The depth of each layer was measured and subsequently sampled and analyzed. Laboratory results are summarized as follows:

Organic Layer (Quantity in railcar estimated to be 5,000-8,500 gallons)
• n-propyl mercaptan = 320,000 mg/kg
• ethoprop = 240,000 mg/kg
• dipropyl disulfide= 97,000 mg/kg
• toluene= 8,300 mg/kg
• TCLP chloroform= 4,900 mg/kg
• Flash point= 3.3 degrees C

Aqueous Layer (Quantity in railcar estimated to be 10,000 – 13,000 gallons)
• n-propyl mercaptan = 110 mg/kg
• ethoprop= 150 mg/kg
• chloroform= 3.6 mg/kg
• Flash point = 22 degrees C

Measurements of the aqueous (liquid) portion of the sample showed concentrations of ethoprop and propyl mercaptan that are consistent with previously reported findings, and a low concentration of chloroform.

Measurements of the organic layer showed high concentrations of ethoprop, propyl mercaptan, and dipropyl disulfide (a breakdown product of ethoprop), and also chloroform and toluene.

As noted above, these results may not represent the exact chemical composition of the waste as it existed at the PSC facility.

However, if a tank at the facility did contain chemicals at these concentrations, the potential health risk to people in the surrounding community would be related to evaporation of chemicals into the air, and not to the concentrations of chemicals in the organic or aqueous layers.

• Propyl mercaptan evaporates quickly at room temperature. Propyl mercaptan vapor can irritate skin, eyes, and mucus membranes; and the very unpleasant, onion-like odor associated with propyl mercaptan can cause symptoms including headache and nausea.

• Ethoprop does not readily evaporate and we have no evidence to suggest that the ethoprop would have gotten into the air.

Therefore, we believe that the ethoprop does not pose a serious health threat to area residents. Ethoprop breaks down on its own over time into propyl mercaptan.

• Dipropyl disulfide does not readily evaporate and therefore is unlikely to have presented a health risk in the community.

• Toluene evaporates at a moderate rate. Based on the sample measurements, it is unlikely that toluene vapor was present at a hazardous level in the community or anywhere outside the immediate area around the tanker truck or containment tanks.

• Chloroform was not detected in previous samples taken at the PSC facility on Aug. 15, 2006.

Its detection in the railcar sample may represent a residue from previous contents of the railcar tank, or a product of chemical reactions in the tank over time.

Based on results from environmental sampling, preliminary analysis of reported symptoms, and the scientific data on the behavior of the chemicals involved, propyl mercaptan was released into the air at the PSC plant in late June and most likely caused symptoms reported in the community.

Memorandum from: Stuart Brown, Director, Division of Public Health, DHR
Carol Couch, Director, Environmental Protection Division, DNR
To: Stakeholders
Date: Sept. 15, 2006