Overview of Contamination Events
Since 2008 to 2024, Mexico has experienced 1,146 cases of hydrocarbon contamination affecting 17.2 million cubic meters of soil, with 79% attributed to Pemex according to data from the Secretariat of Environment and Natural Resources (Semarnat).
The National Inventory of Contaminated Sites reports 577 cases as environmental emergencies and 569 as passive environmental contamination. An environmental emergency is defined by Semarnat as an unexpected event causing the uncontrolled release, fire, or explosion of hazardous materials affecting human health and the environment. Passive environmental contamination refers to sites affected by hazardous material release that hasn’t been remediated promptly, leading to contaminant dispersion and requiring cleanup.
Under emergency classification, 1.6 million cubic meters were contaminated, and 15.6 million cubic meters under passive environmental contamination. Of the 1,146 cases, 259 (22.6%) lack approved environmental remediation programs.
Cases by Administration
Considering full years, the administration of President Andrés Manuel López Obrador (2019-2024) saw an increase in contamination cases compared to his predecessor, Enrique Peña Nieto (2013-2018), though Felipe Calderón Hinojosa’s (2008-2012) period remains the highest with 620 cases. With Peña Nieto, there were 259 cases; under López Obrador, there were 267—a decrease of 58% between the two, and a 3% increase from Peña Nieto to López Obrador.
Regarding environmental remediation, Semarnat data shows that 14% (86) of Calderón’s cases lacked programs; Peña Nieto had 37% (96) without programs, and López Obrador had 29% (77) in the same situation.
Who Contaminates and Where?
The 1,146 contamination cases are attributed to over 300 different companies, including globally recognized firms engaging in hydrocarbon transportation and public institutions. However, Pemex and its subsidiaries have been responsible for the most impactful cases.
Pemex accounts for 668 (58%) contamination events affecting 13,611,919.12 cubic meters of soil—78.9% of the 17,236,999.33 cubic meters contaminated since 2008 in Mexico.
The largest contamination event occurred in 2012 at Pemex’s Ciudad Madero refinery in Tamaulipas, impacting 8.8 million cubic meters.
Notable companies involved in contamination include Kansas City Southern de México, S.A. de C.V; Exxonmobil Comercial, S.A. de C.V; Volkswagen de México, S.A. de C.V; Radiomóvil Dipsa, S.A. de C.V; Bristol-Myers Squibb de México, S. de R.L. de C.V; Bombardier Transportation México, S.A. de C.V; Braskem Idesa, S.A.P.I; and Shell México, S.A. de C.V., among others.
These companies are linked to 20 cases between 2008 and 2021, affecting at least 343,080 cubic meters. Five cases lack approved environmental remediation plans: Radiomóvil Dipsa (Telcel) in 2013 for a heavy oil spill in La Paz, Baja California Sur; Braskem Idesa in 2018 for acid leakage in Nanchital, Veracruz; and Shell México in 2020 for a heavy oil spill at one of its gas stations in Iztapalapa, Mexico City.
Key Questions and Answers
- What is the extent of soil contamination in Mexico due to oil spills? Since 2008, there have been 1,146 cases of contamination affecting 17.2 million cubic meters of soil, with 79% attributed to Pemex.
- What types of contamination events are there? There are environmental emergencies (577 cases) and passive environmental contamination (569 cases).
- How many contamination cases lack environmental remediation plans? 259 (22.6%) of the 1,146 cases do not have approved environmental remediation programs.
- How do contamination cases vary by administration? The López Obrador administration saw an increase in contamination cases from Peña Nieto’s period, though Calderón’s administration had the most events (620).
- Which companies are major contributors to soil contamination? Over 300 companies, including globally recognized firms and public institutions, are involved. Pemex and its subsidiaries have been responsible for the most impactful cases.
- What is the largest oil spill event in Mexico? The largest contamination event occurred in 2012 at Pemex’s Ciudad Madero refinery in Tamaulipas, impacting 8.8 million cubic meters.
- How many cases lack approved remediation plans? Five cases, including those by Radiomóvil Dipsa (Telcel), Braskem Idesa, and Shell México, lack approved environmental remediation plans.
