Microplastic contamination in three environmental compartments of a coastal lagoon in the southern Gulf of Mexico.

The Sontecomapan lagoon (Mexico) is a Ramsar site within the Los Tuxtlas Biosphere Reserve, facing the Gulf of Mexico. Although the site has a protected area status, it is vulnerable to microplastic contamination, whose long-term effects are uncertain. This study gives the first approach to the degree of contamination by microplastics in surface waters, zooplankton, and sediments in the lagoon.

Spatial distribution of PAHs, nickel, and vanadium in sediments from a large coastal lagoon near a petroleum extraction area in the southern Gulf of Mexico.

One of the world's crucial areas for crude oil exploration and extraction is the southern Gulf of Mexico, where Terminos Lagoon (TL) is located. Sediments from the TL region were used to assess the spatial patterns, origins, and ecotoxicological risks associated with 16 priority polycyclic aromatic hydrocarbons (PAHs; 3.1-248.

Simulation of encounter rates between zooplankton organisms and microplastics in a tropical estuary.

Coastal estuarine systems may hold a large number of microplastic particles, which predators often mistake for prey. This study estimated the encounter rates between microplastics (alleged prey) and zooplankton having different feeding modes, trophic positions, swimming velocities, and perception distances, under calm and turbulent conditions, and during two seasons. Surface water samples were taken at 10/12 sites of the Sontecomapan lagoon, southern Gulf of Mexico, to quantify microplastic concentration.

Organochlorine contaminants in sediments and factors influencing their distribution in the natural marine protected area in the gulf of Mexico.

The aim of this study was to determine the concentration of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in marine sediments of a natural marine protected area (NMPA), Veracruz Reef System (VRS), in the Gulf of Mexico (GoM). This NMPA represents one of the first coastal sites with port activity in Mexico, which causes a range of human activities that require adequate planning so as not to impact and destroy this marine protected area; In this sense, this work represents the first effort aimed at diagnosing the presence of organochlorine contaminants in reef sediments from the mainland, both from the adjacent port area and from more distant regions with dominant agricultural activities that ultimately affect this NMPA. Content of organic matter (OM), carbonates and grain-size composition were determined to investigate their influence on compounds distribution in the sediment through multivariate analysis.

The situation of chlorpyrifos in Mexico: a case study in environmental samples and aquatic organisms.

Chlorpyrifos (CPF) is one of the most commonly used organophosphate pesticides. Because CPF was described as a toxic compound without safe levels of exposure for children, certain countries in Latin America and the European Union have banned or restricted its use; however, in Mexico it is used very frequently. The aim of this study was to describe the current situation of CPF in Mexico, as well as its use, commercialization, and presence in soil, water, and aquatic organisms in an agricultural region of Mexico.

Pb geochronology and metal concentrations in sediment cores recovered in the Alvarado Lagoon system, Veracruz, Mexico.

Three sediment cores recovered from the Alvarado Lagoon System (ALS) in the Gulf of Mexico were used to reconstruct the history of metals and metalloids and their environmental importance. The sedimentary profiles were dated with Pb and verified with Cs. Maximum ages of 77 and 86 years were estimated.

Multi-level responses of oysters Crassostrea virginica for assessing organochlorine pesticides in a Ramsar coastal lagoon in southern Mexico.

Organochlorine pesticides (OCPs) have been intensively used without proper regulation and control in Latin America due to the prevalence of diseases and pests, thus posing potential risks to nontarget organisms. Initiatives for ecosystem preservation, such as to designate protected areas, may not be enough to avoid contamination by OCPs, considering that protected areas tend to be permeable to diffuse sources. Here, we investigate multi-level responses of the oyster Crassostrea virginica to OCPs in Laguna de Términos, a RAMSAR coastal lagoon in the southern Gulf of Mexico.

Organochlorine pesticides and polychlorinated biphenyls in high mountain lakes, Mexico.

Pollution levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the El Sol and the La Luna alpine lakes. The lakes are located in central Mexico, in the crater of the Nevado de Toluca volcano. The El Sol and the La Luna lakes are extremely relevant in Mexico and in the world because they are recognized as pristine regions and environmental reservoirs.

Organochlorine pesticides in lacustrine sediments and tilapias of Metztitlan, Hidalgo, Mexico.

The organochlorine pesticides (OP) are very stable molecules, due to this stability; they are very resistant in the environment and highly related to fat tissues with a wide diffusion property and an average time life higher then 10 years. We studied sediments (November 2001, April and June 2002) and organisms collected in April and July (2002) from the lacustric zone of Metzitlán, Hidalgo, Mexico. The analysis was performed according to UNEP/IAEA (1982) (sediments) and UNEP/FAO/IOC/IAEA (1986) (organisms) methods.

Presence, distribution, and origins of polycyclic aromatic hydrocarbons (PAHs) in sediments from Bahía Blanca estuary, Argentina.

This paper is the first comprehensive survey of polycyclic aromatic hydrocarbons (PAHs) in coastal sediments in Bahia Blanca, Argentina, and provides useful information on their levels of concentration, composition, and sources of these pollutants. The total concentrations of PAHs ranged from 15 to 10,260 ng g(-1). The highest contents (mean 3,315 ng g(-1)) of total PAHs in marine sediments were found in the inner channels of the estuary, while the lower ones (204 ng g(-1)) belong to samples collected far away from contamination sources.