San Diego County Faces Multifront Health Threat Due to Transboundary Sewage Flow
A transboundary sewage stream flowing from Tijuana, Mexico, into San Diego County is causing a public health crisis due to contamination in water, air, and soil.
Cross-border Contamination Raises Concerns of Disease Reemergence
The transboundary sewage flow from Tijuana to San Diego County is a result of inadequate infrastructure and urbanization, leading to a public health threat. The contamination poses the risk of diseases that were previously eradicated in California, antibiotic-resistant microbes, and banned industrial chemicals.
Lead author Paula Stigler Granados, an associate professor at San Diego State University, expressed concern about the contaminants becoming aerosolized, which can further spread the pollutants. Aerosolization refers to waterborne pathogens and compounds becoming suspended in the air.
The city of Imperial Beach, located near the border, is particularly affected by the transboundary sewage crisis. The contaminated water not only poses risks to public health but also has socioeconomic and legal implications.
Inadequate Sewage Treatment Facilities on Both Sides of the Border
Insufficient sewage treatment facilities on both the Mexican and U.S. sides of the border contribute to the ongoing sewage flow problem. Mexico has begun overhauling its obsolete facility that releases millions of gallons of sewage into the Pacific Ocean.
However, the South Bay Wastewater Treatment Plant, responsible for treating Tijuana's waste through an international treaty, is also failing to adequately address the issue. Although $300 million has already been allocated for renovating the plant, an additional $150 million is required for it to function properly.
Local officials, including Rep. Scott Peters, have called for Congress to approve President Biden's request for an additional $310 million for the plant's renovation. The lack of progress in addressing the issue has led to consecutive beach closures and significant impacts on the local economy and tourism.
Contaminants in Soil and Water Pose Public Health Risks
Scientists have identified over 170 compounds in the region's soil sediments, including toxic chemicals such as polycyclic aromatic hydrocarbons (PAHs), banned pesticides, heavy metals, and phthalates. Many of these pollutants are known to be persistent, bio-accumulative, carcinogenic, and toxic.
Water samples have revealed the presence of viruses, bacteria, parasites, and antibiotic-resistant genes. Zoonotic pathogens, capable of jumping from animals to humans, have also been found in bottlenose dolphins in the area.
The contamination extends to the region's water, with various organic chemical contaminants detected, including volatile organic compounds, hormones, and flame retardants. Many of these contaminants are new discoveries and raise concerns about public health risks.
