Are anthropogenic factors affecting nesting habitat of sea turtles? The case of Kanzul beach,Riviera Maya-Tulum (Mexico)

Marine coast modification and human pressure affects many species, including sea turtles. In order to study nine anthropogenic impacts that might affect nesting selection of females, incubation and hatching survival of loggerhead (Caretta caretta) and green turtle (Chelonia mydas), building structures were identified along a 5.2 km beach in Kanzul (Mexico). A high number of hotels and houses (88; 818 rooms), with an average density of 16.6 buildings per kilometer were found. These buildings form a barrier which prevents reaching the beach from inland, resulting in habitat fragmentation. Main pressures were detected during nesting selection (14.19% of turtle nesting attempts interrupted), and low impact were found during incubation (0.77%) and hatching (4.7%). There were three impacts defined as high: beach furniture that blocks out the movement of hatchlings or females, direct pressure by tourists, and artificial beachfront lighting that can potentially mislead hatchlings or females. High impacted areas showed lowest values in nesting selection and hatching success. Based on our results, we suggest management strategies to need to be implemented to reduce human pressure and to avoid nesting habitat loss of loggerhead and green turtle in Kanzul, Mexico.     

The progress of interdisciplinarity in invasion science

Interdisciplinarity is needed to gain knowledge of the ecology of invasive species and invaded ecosystems, and of the human dimensions of biological invasions. We combine a quantitative literature review with a qualitative historical narrative to document the progress of interdisciplinarity in invasion science since 1950. Our review shows that 92.4% of interdisciplinary publications (out of 9192) focus on ecological questions, 4.4% on social ones, and 3.2% on social–ecological ones. The emergence of invasion science out of ecology might explain why interdisciplinarity has remained mostly within the natural sciences. Nevertheless, invasion science is attracting social–ecological collaborations to understand ecological challenges, and to develop novel approaches to address new ideas, concepts, and invasion-related questions between scholars and stakeholders. We discuss ways to reframe invasion science as a field centred on interlinked social–ecological dynamics to bring science, governance and society together in a common effort to deal with invasions.     

The impact of pesticides on oxidative stress level in human organism and their activity as an endocrine disruptor

Pesticides cause serious environmental and health problems both to humans and animals. The aim of this review is to discuss selected herbicides and fungicides regarding their mode of action and their influence on basic oxidative stress parameters and endocrine disruption properties tested in selected cell cultures in vitro. Because of numerous difficulties which animal studies are subject to, cell cultures are an excellent experimental model reflecting human exposure to different pesticides through all relevant routes. This experimental model can be used to monitor aggregate and cumulative pesticide exposures.     

Comprehensive estimate of the theoretical maximum daily intake of pesticide residues for chronic dietary risk assessment in Argentina

A chronic dietary risk assessment for pesticide residues was conducted for four age groups of the Argentinian population following the procedure recommended by the WHO. The National Theoretical Maximum Daily Intake (NTMDI) for 308 pesticides was calculated for the first time, using the Maximum Residue Limits (MRLs) from several Argentinean regulations and food consumption data from a comprehensive National Nutrition and Health Survey. The risk was estimated by comparing the TMDI with the Acceptable Daily Intakes (ADI) identified by various sources. Furthermore, for each of the compounds with a TMDI >65% of the ADI, a probabilistic analysis was conducted to quantify the probability of exceeding the ADI. In this study 27, 22, 10, and 6 active ingredients (a.i.) were estimated to exceed the 100% of the ADI for the different population groups: 6–23 month-old children, 2–5 year-old children, pregnant women, and 10–49 year-old women, respectively. Some of these ADI-exceeding compounds (carbofuran, diazinon, dichlorvos, dimethoate, oxydemeton-methyl and methyl bromide) were found in all four of these groups. Milk, apples, potatoes, and tomatoes were the foods that contributed most to the intake of these pesticides. The study is of primary importance for the improvement of risk assessment, regulations, and monitoring activities.     

Risk estimation to human health caused by the mercury content of Sushi and Sashimi sold in Japanese restaurants in Brazil

Although fish is a healthy alternative for meat, it can be a vehicle for mercury (Hg), including in its most toxic organic form, methylmercury (MeHg). The objective of the present study was to estimate the risk to human health caused by the consumption of sushi and sashimi as commercialized by Japanese food restaurants in the city of Campinas (SP, Brazil). The total Hg content was determined by atomic absorption spectrometry with thermal decomposition and amalgamation, and the MeHg content calculated considering that 90% of the total Hg is in the organic form. The health risk was estimated from the values for the provisional tolerable weekly ingestion (PTWI) by both adults and children. The mean concentrations for total Hg were: 147.99, 6.13, and 3.42 µg kg^?1 in the tuna, kani, and salmon sushi samples, respectively, and 589.09, 85.09, and 11.38 µg kg^?1 in the tuna, octopus and salmon sashimi samples, respectively. The tuna samples showed the highest Hg concentrations. One portion of tuna sashimi exceeded the PTWI value for MeHg established for children and adults. The estimate of risk for human health indicated that the level of toxicity depended on the type of fish and size of the portion consumed.     

Design of water quality monitoring networks with two information scenarios in tropical Andean basins

Design and redesign of water quality monitoring networks were evaluated for two similarly sized watersheds in the tropical Andes via optimization techniques using geographic information system technology (GIS) and a matter-element analysis of 5-day biological oxygen demand (BOD₅) and total suspended solids (TSS). This resulted in a flexible, objectively based design for a 1128-km² watershed without prior water quality data (La Miel River), and a network redesign of a 1052-km² watershed with historical water quality monitoring (Chinchiná River). Monitoring design for the undocumented basin incorporated mathematical expressions for physical, anthropological, and historical factors—and was based on clear objectives for diagnosis and intervention of water pollution. Network redesign identified network redundancy, which resulted in a 64% reduction in the number of water quality monitoring stations along the channel, and a 78% reduction of stations throughout the basin. Most tropical drainage basins throughout the world have little to no prior water quality data. But even in well-studied drainage basins like the Chinchiná River, which is among the most thoroughly studied basins in Colombia, redesign of historical and existing monitoring networks will become a standard tool to advance the restoration of polluted surface waters, not only in Colombia, but also throughout the world.     

Triclocarban: UV photolysis,wastewater disinfection,and ecotoxicity assessment using molecular biomarkers

Triclocarban (TCC) is an antibacterial agent found in pharmaceuticals and personal care products (PPCP). It is potentially bioaccumulative and an endocrine disruptor, being classified as a contaminant of emerging concern (CEC). In normal uses, approximately 96% of the used TCC can be washed down the drain going into the sewer system and eventually enter in the aquatic environment. UV photolysis can be used to photodegrade TCC and ecotoxicity assays could indicate the photodegradation efficiency, since the enormous structural diversity of photoproducts and their low concentrations do not always allow to identify and quantify them. In this work, the TCC was efficiently degraded by UVC direct photolysis and the ecotoxicity of the UV-treated mixtures was investigated. Bioassays indicates that Daphnia similis (48 h EC₅₀ = 0.044 μM) was more sensitive to TCC than Pseudokirchneriella subcapitata (72 h IC₅₀ = 1.01 μM). TCC and its photoproducts caused significant effects on Eisenia andrei biochemical responses (catalase and glutathione-S-transferase); 48 h was a critical exposure time, since GST reached the highest activity values. UVC reduced the TCC toxic effect after 120 min. Furthermore, TCC was photodegraded in domestic wastewater which was simultaneously disinfected for total coliform bacterial (TCB) (360 min) and Escherichia coli (60 min).

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Graphical abstract TCC degradation and ecotoxicological assessment

     

Evaluation of the sensitivity spectrum of a video tracking system with zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) exposed to five different toxicants

The aim of this study was to develop a biological early warning system for the detection of aquatic toxicity and test it with five toxicants with distinct chemical nature. This was done in order to verify the spectrum of sensitivities of the proposed system, as well as the potential identification capability of the tested contaminants, using only the analysis of zebrafish’s behavior. Six experimental conditions were tested: negative control and five toxicants (bleach, lindane, tributyltin, mercury, and formaldehyde). The exposure time was 45 min, and the concentrations used corresponded to 9% of LC₅₀’s-96 h for the tested compounds, to ensure ecologically relevant results. A total of 108 fish were used, with each individual experimental condition being tested 18 times. A statistical model of diagnosis was used, combining self-organizing map and correspondence analysis. The values of sensitivity, specificity, accuracy, false positive, false negative, positive predictive value (PPV), and negative predictive value (NPV) were calculated. The objectives of the work were accomplished and the system showed a good overall diagnostic performance with 79% in accuracy, 77% in sensitivity, and 88% in specificity. The lowest result of the predictive values was 78% (lindane and mercury), in the case of the NPV, and 86% (bleach and lindane), in the case of the PPV. The best result of the predictive values was 100% (bleach and tributyltin), for the NPV, and 89% (tributyltin), for the PPV. Regarding the five tested toxicants, the system was able to correctly identify the agent responsible for the contamination in 40% of the positive diagnoses.     

Dental enamel as biomarker for environmental contaminants in relevant industrialized estuary areas in São Paulo,Brazil

Heavy metal contamination is a long-standing and very well-known public health problem, and its exposure can cause damage to several organs of human body, especially on the central nervous system of young children and teenagers. The aim of this article is to evaluate lead, cadmium, and manganese contamination in 125 children from 6 to 13 years old living in contaminated areas during the period from 2006 to 2009 (São Vicente, Cubatão Downtown, Bertioga and Cubatão Pilões/Água Fria). This estuary area is the most important example of environmental degradation by chemicals from industrial sources. This is a cross-sectional study through clinical examinations and dental enamel tests. All mothers from these children lived in the area since before the pregnancy. Lead, cadmium, and manganese levels (μg/g) were measured on dental enamel samples through graphite furnace atomic absorption spectrometry, searching for the occurrence of heavy metals. The mean lead concentrations were 139.48 μg/g in Cubatão Pilões/Água Fria, 170.45 μg/g in Cubatão Downtown, 213.52 μg/g in São Vicente, and 151.89 μg/g in Bertioga. The mean cadmium concentrations were 10.83 μg/g in Cubatão Pilões/Água Fria, 12.58 μg/g in Cubatão Downtown, 10.92 μg/g in São Vicente, and 14.57 μg/g in Bertioga. The mean manganese concentrations were 23.49 μg/g in Cubatão Pilões/Água Fria, 30.90 μg/g in Cubatão Downtown, 41.46 μg/g in São Vicente, and 42.00 μg/g in Bertioga. Dental surface enamel may be used as an efficient biomarker of past environmental exposure to lead, manganese, and cadmium which are associated to well-known sources of heavy metal contamination. The results suggest that the evaluated children were exposed to sources of lead, cadmium, and manganese since before their conceptions. Although Bertioga initially was chosen as a control area of this study, it was also was verified to have heavy metal contamination on examined children.     

Genotoxicity in adult residents in mineral coal region—a cross-sectional study

The present study assessed the DNA damage in environmentally exposed volunteers living in seven municipalities in an industrial coal region, through the use of the comet assay with blood cells and the micronucleus test with buccal cells. Blood and buccal smears were collected from 320 male volunteers living in seven cities inserted in a coal region. They were ages of 18 and 50 years and also completed a questionnaire intended to identify factors associated with DNA damage through a Poisson regression analysis. The comet assay detected significant differences in DNA damage in volunteers from different municipalities, and neighboring cities (Pedras Altas, Aceguá, and Hulha Negra) had a higher level of DNA damage in relation to control city. Some of the risk factors associated with identified DNA lesions included residence time and life habits. On the other hand, the micronucleus test did not identify differences between the cities studied, but the regression analysis identified risk factors such as age and life habits (consumption of mate tea and low carbohydrates diet). We conclude that there are differences in the DNA damage of volunteers from different cities of the carboniferous region, but the presence of micronuclei in the oral mucosa does not differ between the same cities. Furthermore, we alert that some related factors may increase the risk of genotoxicity, such as residence location and time, and living and food habits. Finally, we suggest the need for continuous biomonitoring of the population, as well as for investing in health promotion in these vulnerable populations.