Researchers from San Diego State University and UC San Diego are back in the Tijuana River Valley after pulling out last week over health concerns arising from toxic gases they detected in the air. Last week, they announced a temporary halt to their work when their monitors detected hydrogen sulfide and hydrogen cyanide in the air. Citing health concerns, researchers felt it was in their best interests to leave the area until further testing could be done. Almost immediately, the County of San Diego disagreed with the researchers and quickly released its own data gathered by its own monitors.

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