Insights from the Latin America Session at the SETAC North America Meeting

Adriana C. Bejarano, National Oceanic and Atmospheric Administration; Martha Georgina Orozco Medina, University of Guadalajara; Patricia Ramirez Romero, National Autonomous University of Mexico; and Marcela Galar Martínez, Escuela Nacional de Ciencias Biológicas

The SETAC North America 45th Annual Meeting in Fort Worth, Texas, brought together more than 1,500 scientists from 30 countries, and included a broad range of topics across 184 scientific sessions. One of these sessions focused on “Emergent Environmental Issues and Perspectives in Latin America.” In this region, multiple factors drive environmental impacts, including regulated and unregulated resource extraction, poor solid waste management and untreated discharges to water bodies, increased demand for goods and services, industrialization, rapid urbanization, and the expansion of the agricultural frontier. In addition, regulatory frameworks with limited environmental enforcement and oversight intensify threats from these and other pressures.

This session included six plenary presentations and 13 posters addressing pressing environmental issues in Latin America, all united by a common focus on water quality..

Mexico: There were several platform presentations from this country. One study evaluated contaminant concentrations in groundwater, Yucatan's only drinking water source. This study found low concentrations of pesticides, polycyclic aromatic hydrocarbons and nutrients, with no toxic effects to Allium cepa (onion). Another study evaluated the toxicity of water from the Madín Dam, a water reservoir in Mexico City and the source of drinking water for more than 20 million people. Water samples from one site caused mortality to zebrafish larvae, while samples from all sites induced acetylcholinesterase activity and reduced locomotor activity, indicating negative impacts of water contaminants on neurological function. A related study focused on characterizing microplastics in water wells used for human consumption and domestic activities in rural communities of the State of Tlaxcala. Microplastics from several polymer classes (i.e., polypropylene, polystyrene, polyvinyl chloride and polyethylene terephthalate) were found in the 2,100-4,400 μm length range, with an average concentration of 0.34 particles per liter. Domestic, agricultural and industrial waste, and inefficient urban solid waste and wastewater management may contribute to groundwater microplastic pollution. Other studies from Mexico were presented in poster format. One poster showed emerging pollutants, particularly pharmaceuticals and personal care products, in water from cenotes (sinkholes) in Yucatan, documenting high concentrations of an active ingredient found in insect repellent. This study found the presence of untreated wastewater of human origin in all the cenotes studied. Another poster presented water quality measurements from a segment of the Tecolutla River (e.g., temperature, pH, dissolved oxygen, dissolved solids, electrical conductivity, biochemical oxygen demand) and toxicity testing using wheat seeds. Nutrient concentrations did not meet the quality standard values according to Mexican regulations and were probably related to presence of untreated wastewater. Another study evaluated the use of hydrophytes in the removal of heavy metals (e.g., lead and cadmium) from wastewater, reporting that the invasive hydrophyte Egeria densa has good adsorbent characteristics, and had higher heavy metal removal efficiency than other materials (i.e., sugarcane, bagasse, orange peel). The presence of this species in the Valles River and other rivers in Mexico could prove useful in mitigating metal contamination, while serving as a mechanism for their control. Another poster highlighted the impact of the intensification and frequency of droughts on the availability of freshwater resources for industrial processes and domestic use, and water quality. The moderate to severe drought conditions that have affected Mexico in recent years have not been mitigated by the intensification of the rainy season and represent an area of concern for public health and water management. Two posters emphasized the importance of education as a mechanism to increase environmental awareness. One study described the dissemination of scientific knowledge through the publication and distribution of magazines and participation in forums, festivals and fairs in public spaces, including schools, parks and squares in rural and urban areas. Another study focused on increased awareness among secondary school students on relevant environmental issues faced by the municipality of La Piedad, Michoacán, including deforestation, inadequate solid waste management, pollution of the Lerma River, and stray dog overpopulation. A key component of this work was the development of guidelines and plans that could be used to implement solutions to these local issues.

Costa Rica: One poster evaluated the utility of silicone wristbands in assessing human exposure to flame retardants and pesticides, and it contrasted exposures in agricultural settings between Costa Rica and Uganda. Surveys showed that most chemicals had higher concentrations in samples from Costa Rica than in those from Uganda, possibly due to extensive pesticide use, rapid urbanization and industrialization in Costa Rica, and the nature of small-scale farming in Uganda.

Ecuador: Studies from this country were presented in poster format. Three of the studies focused on characterizing contaminants (metals, metalloids and microplastics) in mangrove ecosystems. One ongoing study characterized metals and metalloids in sediment, mussels and clams from two locations, including dietary intake surveys from residents. The second study focused on the use of barnacles as bioindicators of the presence and abundance of microplastics, aiming to establish a cost-efficient monitoring program for microplastics. The third study evaluated microplastic pollution in wild-caught mussels, finding that fibers and filaments were the most abundant type of microplastics.

Argentina: The platform presentation from this country summarized the source and scale of pesticide contamination in water and fish tissues of four fish species found in the Pergamino River. This study found 44 pesticides in surface water, complex pesticide mixtures in every sampling date, and 20–30 different pesticides in fish tissues. This study provides evidence of water contamination by currently used agricultural pesticides in the Pampa region.

Chile: The platform presentation from this country focused on a study on the Bíobío River, a hotspot of native fish diversity and an important water source for more than one million people in Concepcion, Chile’s second-largest city. This river is impacted by urban and industrial wastewater, with evidence of endocrine disruption across different levels of biological organization, from molecular mechanisms to population impacts. This study highlighted the need to bridge the gap between science and regulatory measures by considering effects-based assessments, stakeholder engagement and involvement, and an understanding of this unique river ecosystem. Three additional studies were presented in poster format. One study evaluated the occurrence of perchlorate and thiocyanate in drinking water, finding that these chemicals are common contaminants in drinking water and that residents of northern Chile were exposed to higher doses than populations from other regions. A related study assessed the occurrence of bromate in drinking water and vegetables, finding that bromate is a common contaminant in both tested media, with residents of northern regions being exposed to higher doses than residents from other regions. The third poster evaluated the concentration of Ochratoxin A levels in single and mixed spices consumed in Chile, finding high occurrence and variable levels over time, with many samples exceeding established international limits for consumption.

The Latin America session provided an opportunity to share environmental issues, mainly around water quality, and strengthen collaboration and partnerships among scientists in the region. This and related sessions could help identify potential joint projects and enhance interdisciplinary research through shared experiences and approaches among countries with similar issues. These types of exchanges enable capacity building and strengthen scientific outcomes, ultimately improving human and environmental health.

Although only three percent of all attendees were from emerging market economies and developing countries, these individuals collectively represented 40 percent of the country’s diversity at the meeting. Their participation highlights the need to include sessions focusing on emerging market economies and developing countries in future SETAC North America meetings. This Globe article also serves as an open invitation to collaborate in organizing such sessions in future meetings.

Author’s contact: [email protected]