SAN DIEGO (Border Report) — Researchers from San Diego State University are launching the second phase of a survey as they study the effects of pollution on Tijuana River Valley residents.

For decades, the Valley has been plagued by untreated sewage flows that originate in Mexico.

The Tijuana River not only carries the effluent, but also large quantities of chemicals and other pollutants into the U.S. side of the border and the Tijuana River Valley.

In recent years, the contamination has gotten worse as Tijuana’s sewage infrastructure has collapsed and is constantly sending millions of gallons of raw sewage north of the border.

On a daily basis, the stench can be overwhelming.

“The smell indicates there is exposure happening,” said Dr. Paula Stigler Granados, one of the lead researchers from SDSU.

Since last year, Granados and other scientists have been detecting dangerous levels of hydrogen sulfide and other gases in the air throughout the Tijuana River Valley.

They believe the gases come from the sewage and chemicals that are being churned by the water in the river, especially in areas where it cascades.

Five months ago, Granados and her team began an online survey of residents trying to figure out the extent of the pollution’s effect on the public.

“About 70% of households reported some form of respiratory illness and the ones that reported smelling daily odors, or at least four to five times a week, had a higher response rate of having respiratory illnesses and gastrointestinal illnesses.”

Granados is looking for wider participation from those who live along the Valley and in other areas in south San Diego County.

“Right now, out of everybody who completely responded and completely filled out the survey, it’s only close to 400 people,” she said. “What we really need is to have thousands of people.”

According to Granados, Phase 2 of the survey has been restructured as they look for more responses and other vital information.

“We’ve tightened it down, made it more simple and added a few questions about pets and horses,” she said. “And we’ve also added a question about filters in case anybody received a purifier from the county they can tell us if they received it and if it’s working.”

Granados says the goal is to help people and keep them informed.

“What we want to do is give data back to the community, we are planning to have an online community forum at the end of March and we’re partnering with some physicians and medical students over at UCSD to also help share some resources about having to take care of themselves if you live in these areas.”

She also stated the data will be shared with public agencies.

“The best we can do is just keep giving this data to the government, they’re the ones who can make the changes.”

For more information about the survey, its findings and participation, log onto tjriver.sdsu.edu.