San Diego State University researchers unveiled early results on Tuesday of a new survey about what it’s like to live near the sewage-laced Tijuana River. More than 500 people living in Imperial Beach, Nestor, San Ysidro and as far north as Coronado and National City took the Healthy Water, Healthy Air survey. … “Nausea, headaches, brain fog, stomach issues, anxiety, tiredness, sleep problems: a lot of this has been reported by people taking the health survey,” said Paula Stigler Granados, one of the lead researchers behind the survey and an associate professor at SDSU. … Early results show that when sewage spills into the river, more hydrogen sulfide is detected, and more people feel ill. Conditions worsen depending on the weather and season.