SAN ANTONIO – February 6, 2009 (Express-News) -- To the average onlooker, the white bus parked outside Victor San Miguel's home could specialize in carpet cleaning.
That might explain the vacuum tube running from the bus through the home's front door. But this tube isn't sucking out dirt. Instead, it's siphoning air to a battery of high-tech equipment in the bus that is searching for traces of dangerous chemicals that could be seeping into the house from the toxic brew of pollutants that flows beneath the neighborhood.
This is the second and possibly final time the Environmental Protection Agency's specialized mobile unit has made the trip from New Jersey to test the air in homes around the defunct Kelly AFB. Crews tested 11 homes this week, trying to determine if potentially cancer-causing toxins could be migrating through the soil and collecting in the homes above. Results won't be available for at least two months.
San Miguel has hopes that the tests will finally prove that there is a silent and invisible killer in his neighborhood. That's a common belief on the working-class streets around Kelly. Many of the modest homes on Hollenbeck Street, where San Miguel has lived for three decades, sport purple crosses in memory of those who have died from cancer and other diseases. Residents here believe the diseases are linked to the pollutants from the base, which closed in 2001.
The Agency for Toxic Substances and Disease Registry has found high rates of liver, lung and kidney cancer and other illnesses in the neighborhoods around the base. But none of the epidemiological studies conducted in the area have linked the disease rates with the pollutants that flow under the homes.
“I don't know much about science, but there are 13 homes on this block and 11 of those families have had someone die from cancer,” San Miguel said. “That is what is bothering me. Where did that come from?”
The plume of chemicals that runs beneath this neighborhood stretches at least five miles to the south and east of the base and lies under more than 20,000 homes and businesses. The chemicals leached into the ground over decades of aircraft operations at Kelly, although it is possible that nearby industrial businesses have contributed to the pollution. The toxic chemicals are contained in the shallow aquifer, but not the Edwards Aquifer, which supplies the area's drinking water.
The chemicals being tracked are trichloroethylene (TCE), perchloroethylene (PCE) and dichloroethylene (DCE). The first two are thought to be human carcinogens, according to the toxic substances agency.
Similar tests of five homes in May didn't show anything that alarmed EPA officials, although two of the 10 air quality tests done then did show chemical vapors at or slightly higher than federal screening levels. The EPA decided to come back in the winter to determine if there was any seasonal variation to the air quality.
“We were not satisfied with the summer sampling and wanted them back in winter because that is when people have their homes closed up and their heaters on,” said Robert Alvarado, whose home on nearby Baker Street was also tested. “Although it is not cold today.”
If results are similar this time, it is unlikely the mobile unit will return, said the EPA's Gary Miller.
The results will probably be released at the Kelly Restoration Advisory Board's April meeting.