Environmental Risks and Children's Health in a Mayan Community from Southeast of Mexico

Clinical and laboratory features of rickettsioses in Yucatan, Mexico

Rickettsia species are obligate intracellular bacteria that can cause mild to severe human disease. Based on phylogeny, clinical symptoms, and antigenic properties, rickettsiae are classified into four groups. Infections by these agents are characterized by clinical symptoms ranging from self-limited to severe and even fatal febrile illnesses, depending on the Rickettsia spp. involved, the patient's predisposition, and timely medical care. The present study aimed to characterize rickettsial diseases in Yucatan according to clinical and laboratory features appearing in medical records corresponding to 427 samples taken between 2015 and 2018. A study was conducted over the period 2015-2018 on 427 samples. Clinical and laboratory features were documented from the patients' medical records. For molecular diagnosis, blood was collected in 3.8 % sodium citrate as anticoagulant, and DNA was extracted. Single-step and nested PCR amplification was performed using genus-specific primers for the rickettsial 17kDa and ompB genes. The amplicons obtained were purified and sequenced. A total of 22.7 % (97/427) positive cases of Rickettsia spp. were identified by PCR from 14.15 % (15/106) of the municipalities in Yucatan. 75.2 % (73/97) of the cases were from the city of Merida during the autumn (September-December). The age groups with the highest frequency of confirmed cases were pediatric (5-14 years) (57.7 %) and adults (25-49 years) (42.2 %). There were six fatal cases in children, one associated with R. typhi and five with R. rickettsii. In non-fatal cases, 32.9 % (32/97) corresponded to the spotted fever group (SFG), and 60.8 % (59/97) to the typhus group (TG). Significant differences in signs, and laboratory data, were observed between the pediatric and adult populations. For the treatment of patients, oral and intravenous doxycycline was used in severe hospitalized cases. Typhus group and spotted fever group Rickettsiae are endemic pathological agents found in urban and rural areas of our region. Molecular identification allows for greater diagnostic accuracy and timely treatment and consequently a better prognosis. It is necessary to implement or reinforce measures focused on the dissemination of knowledge regarding rickettsial diseases and their prevention.

Agricultural pesticide residues in water from a karstic aquifer in Yucatan, Mexico, pose a risk to children's health

Yucatan is a region with a high impact of water contamination since it has a karst type soil favoring contaminants entry into the phreatic level, the only source of freshwater in the area. However, no studies report pesticides in water for human consumption or the risk it represents. The objective of this study was to detect and measure pesticide concentrations in domestic tap water to estimate the risk (carcinogenic and non-carcinogenic) to health. A non-probabilistic sampling was applied of 48 tap water sources, and then pesticide detection with solid-phase extraction gas chromatography coupled to the electron capture and flame photometric detectors allowed the estimation of risk through hazard ratios. The present results suggest that aldrin, heptachlor, and β-BHC residues in domestic tap water from Ticul, Yucatan, pose a risk to children's health, particularly for potential carcinogenic risks.

Greening the Browns: A Bio-Based Land Use Framework for Analysing the Potential of Urban Brownfields in an Urban Circular Economy

The Circular Economy (CE) is expected to accelerate the use of resources with bio-based origin. Cities have an important role in such an economy, not only as main consumers but also because vegetation provides numerous ecosystem services essential for the well-being of urban dwellers. Urban lands are, however, heavily burdened with both past and present activities and ongoing urbanization. Retrofitting obsolete and potentially contaminated brownfields provides an opportunity to engage with bio-based land uses within the city. At the same time, plants are an important part of Gentle Remediation Options (GROs), a more sustainable alternative for managing contamination risks and restoring soil health. This paper (1) provides a tentative selection of Urban Greenspaces (UGSs) relevant for brownfields, and a compilation of ecosystem services provided by the selected UGSs, and (2) presents a framework covering the 14 selected bio-based land uses on brownfields, including GRO interventions over time. This framework provides three practical tools: the conceptualization of linkages between GROs and prospective UGS uses, a scatter diagram for the realization of 14 UGS opportunities on brownfields, and a decision matrix to analyze the requirements for UGS realization on brownfields.