In Galena Park, east of the 610 freeway and north of the Ship Channel, lifelong residents have an increased cancer risk that's between 90 and 250 times greater than what many scientists consider acceptable, according to a new community air study.

The nonprofit Air Alliance Houston looked at small particles in the community, which is nestled among petrochemical titans, and found the gravest cancer threat in the air could come from mere ships and trucks.

Bel Vasquez-St. John, who helped conceive the project and has worked in Galena Park for more than a decade, said she wouldn't be surprised if trucks were now the community's biggest concern, especially on Clinton Drive, which runs parallel to the Ship Channel on its north flank.

"It's like Clinton Drive is the actual entrance to the Port," she said. "Trucks constantly are lining up so they can deliver or pick up."

Galena Park once was home to seamen and longshoremen, back when unloading a ship took days. Now more people are just passing through. Truck traffic has increased, and it takes its toll on Galena Park's infrastructure, which in turn has become a drag on the economy of the tiny city.

The community air measurement project comes at a sensitive time. The federal government will decide at the end of the year which American cities and regions should be required, at significant expense, to begin removing small particles of soot from the air because they are out of "attainment," or compliance, with federal air pollutant limits. These cities will have to submit plans to the Environmental Protection Agency, committing to enforceable measures to cut down on emissions.

Some environmental scientists here have long been skeptical about what they consider to be a thin network of official air gauges. They question whether it is adequate for measuring true particle levels across the Houston-Galveston area.

In some neighborhoods, community leaders in Houston go even further, claiming that holes in the monitoring web are deliberate and that results from a key monitor may have been doctored by paving around it and putting in landscaping to reduce particle counts.

Because some in Galena Park have felt for a long time that their community is likely to be undercounted, the Air Alliance sought to augment the sole monitoring station there on Clinton Drive, operated by the city of Houston. The five temporary air gauges the nonprofit set up were on top of the Galena Park police station, at City Hall, at the Head Start preschool, and on the recreation and community center.

Elemental carbon

The data they collected did not contradict the official monitor - but roughly confirmed it.

"No statistical difference was found between concentrations at this site and the Air Alliance Houston monitors," said a report prepared by Rice University's environmental statistics unit, which studied the data.

But that does not mean the temporary air stations have no story to tell.

Air Alliance Houston also asked the laboratory to run an analysis of something called elemental carbon. When the amount of elemental carbon is known, scientists can calculate how much of the pollution in a given place is likely to come from diesel engines. Diesel engine exhaust is increasingly viewed by researchers as an important health hazard.

It's more complicated than it looks. It can contain arsenic, benzene and formaldehyde, and has the potential to contribute to mutations in cells that can lead to cancer, according to the Office of Environmental Health Hazard Assessment in California, which says "long-term exposure to diesel exhaust particles poses the highest cancer risk of any toxic air contaminant."

More studies planned

Rice University then took the estimated diesel emissions and translated that into cancer risk. The highest risks were calculated at the air station on the Galena Park police station and at the Head Start preschool.

Thomas Stock, an exposure expert at the UT School of Public Health, reviewed the data that showed the increased cancer risk to be between 90 and 250 times greater than what many scientists consider acceptable - which is defined as one extra cancer per one million people. Stock said he believes the increased cancer risk from diesel is the project's most important yield, even if the limited data does beg for further study.

"Certainly they are concentrations we should worry about," he said. "Everything points to diesel traffic as being the biggest risk for this community."

Air Alliance Houston plans future community air measurement projects focused on small particles in the Pleasantville neighborhood near Galena Park, just inside the 610, and in Pasadena.