Mexico orders Ferromex to remediate chemical spill in Sonora after several intoxications

Mexico's Ministry of Environment and Natural Resources (Semarnat) has mandated that the railway company Ferromex develop an environmental characterization and remediation plan following a significant chemical spill in Naco, Sonora. The incident occurred when a train derailed, causing a tank car carrying about 72,000 liters of sodium hydrosulfide (NaHS) to spill approximately 70,300 liters into an arroyo, or dry creek bed.

Semarnat reported that the spill initially affected an estimated 1.7 square kilometers, with a directly impacted area of 5,207 square meters identified by the Federal Attorney for Environmental Protection (Profepa). Health authorities have confirmed several individuals experiencing symptoms consistent with intoxication, including vomiting, diarrhea, headaches, and respiratory issues. The exact health status of those affected has not yet been released.

Profepa conducted aerial surveillance using drones along 10 kilometers of the arroyo. While no surface evidence of the spill was detected, the agency cautioned that the presence of contaminants cannot be ruled out. Field inspections and sample collection, including soil and arthropod fauna, were carried out at five different points to assess the environmental impact.

Ferromex is now required to submit a comprehensive plan to address the contamination. The results of laboratory analyses on the collected samples will be crucial in determining the full extent of the environmental damage and the specific measures the company must implement to rectify the situation, ensuring compliance with current environmental regulations.