Sara Villanueva-Viramontes

Heavy metal contamination in agricultural production is a significant public health issue in Mexico, as it directly impacts food safety and population exposure through dietary intake. Available scientific evidence indicates that vegetables and other plant-derived foods can serve as significant exposure pathways for toxic elements such as arsenic, cadmium, lead, chromium, and mercury. The consumption of contaminated foods may contribute to cumulative adverse health effects, including neurological, renal, and reproductive alterations, as well as an increased risk of chronic diseases. In Mexico, risk assessment is further constrained by methodological heterogeneity across studies and by difficulties in translating scientific evidence into concrete regulatory actions. Critically, the national regulatory framework lacks specific standards establishing maximum permissible limits for heavy metals in fresh fruits, vegetables, and grains, despite their central role in the population’s diet. Regulations focus primarily on drinking water quality and selected processed foods, creating a regulatory gap in the direct control of contaminants in crops. The findings underscore the urgent need to strengthen public policies by establishing crop-specific regulatory standards, implementing systematic monitoring programs, and integrating food safety considerations more effectively into environmental, agricultural, and public health policies in Mexico.

El artículo analiza la relación entre la percepción social de la contaminación atmosférica y la bioacumulación de metales pesados en frutos como la guayaba y el guamúchil de árboles urbanos, así como los riesgos asociados para la salud en el Área Metropolitana de Guadalajara. A través de encuestas se encontró que el 71 % percibe el aire contaminado, 85 % reconoce la capacidad de los árboles para acumular metales pesados y 64 % consume frutos de guamúchil o guayaba, pese a que 63 % manifiesta preocupación por su posible contaminación. El análisis químico mostró que, en comparación con los frutos de guayaba, los de guamúchil presentan concentraciones significativamente más altas de Mn, Cr, Pb, Zn y Ni (132.77, 82.14, 40.34, 33.01 y 22.41 mg kg⁻¹, respectivamente) superando el índice de riesgo no cancerígeno total (THQ < 1) en mujeres (1.26) y hombres (1.13). Asimismo, el riesgo cancerígeno total fue elevado con valores de 2.45 × 10⁻³ en mujeres y 2.20 × 10⁻³ en hombres, clasificados por la Agencia de Protección Ambiental (EPA, por sus siglas en inglés) como nivel de riesgo alto. Estos resultados respaldan la necesidad de implementar programas de comunicación basados en evidencia científica para informar a la población sobre el consumo de frutos de árboles urbanos según la calidad ambiental del entorno.

Lake Chapala is the main freshwater reservoir in Mexico and faces notable environmental pressure associated with urban, industrial, and agricultural activities, with documented evidence of heavy metal contamination. Thus, the artisanal fishers from Lake Chapala occupy a strategic position for understanding the socio-environmental dynamics of this lacustrine system. The objective of this study was to analyze their perceptions of pollution in Lake Chapala and the health risks associated with heavy metal contamination, with particular emphasis on the consumption of charal (Chirostoma spp.). Based on the results, 70% of fishers agreed that Lake Chapala is polluted, and 50% identified solid waste as the main source of contamination. Regarding water quality, 41% considered that it had not changed in recent years, while 37% perceived that it had deteriorated. With respect to heavy metals, 50% reported being aware of their presence in the lake; however, slightly more than 50% expressed concern about the possibility that charal could be contaminated. Fishers acknowledged the environmental pressure faced by Lake Chapala but prioritized risks based on visibility and their everyday experiences. Incorporating the perceptions of key stakeholders is essential for addressing socio-environmental problems, strengthening environmental communication and public health strategies, and effectively managing this lacustrine system.

Heavy metal pollution in urban environments and public understanding of these contaminants pose major challenges for air-quality management. Urban trees have been proposed as tools to mitigate air pollution; however, evidence integrating biophysical assessments and social perception is still limited in the Guadalajara Metropolitan Area (AMG), Mexico. This study evaluated Cd and Pb accumulation in the leaves of five common urban tree species and assessed residents’ perceptions of air pollution and the role of urban trees. Significant interspecific differences were found, with Citrus × aurantium L. showing the highest Cd concentration (2.60 mg kg⁻¹) and Bauhinia variegata L. the highest Pb content (7.45 mg kg⁻¹). Socially, 62% of respondents found the AMG to be one of the most polluted metropolitan areas in the country, and >90% acknowledged direct or indirect health impacts associated with air pollution; nevertheless, a marked knowledge gap persisted about specific contaminants such as Cd and Pb. This “perception paradox” highlights an opportunity to strengthen risk communication and environmental education and suggests that urban-tree biomonitoring can provide locally meaningful evidence to support public engagement and policy actions. Taken together, the environmental and social findings provide an interpretive, metropolitan-scale synthesis that informs air quality management and public health protection in the AMG.