Detection of Pharmaceutically Active Compounds in Tap Water Samples by Direct Injection HPLC/MS-MS: A Danger Signal in Deficiency in Residue Management.

To date, there is an increased risk to public health and the environment due to the presence of pharmaceutically active compounds within drinking water supply and distribution networks. Owing to this, a direct injection-HPLC/MS-MS method was developed for the simultaneous determination of 16 active pharmaceutical compounds in tap water samples: amoxicillin, ampicillin, cephalexin, cefotaxime, cefuroxime, ciprofloxacin, clarithromycin, clindamycin, chloramphenicol, cyproterone, erythromycin, flutamide, spironolactone, sulfamethoxazole, tamoxifen, and trimethoprim. Limits of detection (LOD) ranged from 0.2 to 6.0 µg/L while quantification limits (LOQ) from 0.3 to 20 µg/L. Recovery percentages were between 70 and 125%. Total analysis time was short, with all compounds being resolved in less than 2.1 min. Of the 22 tap water samples collected and analyzed, the highest concentrations corresponded to amoxicillin (147 µg/L) and ciprofloxacin (44 µg/L). The findings could set a precedent for establishing safe levels of these compounds and increasing standards for tap water quality in this region.

Study of feces of neotropical otters (Lontra longicaudis) in the Ayuquila-Armería basin, Mexico as biomonitors of the spatiotemporal distribution of pesticides.

The pesticides used have contributed to increasing food production; it has also caused them to be found in most ecosystems and have negative effects on biota. The neotropical otter (Lontra longicaudis) is vulnerable to pesticide accumulation and is characterized by being elusive, so it is necessary to address the use of indirect techniques that evaluate its populations' state in an efficient, logistically simple, and non-invasive way. This study aimed to determine the concentration of 20 pesticides in neotropical otter feces in the Ayuquila-Armería basin and to describe the spatiotemporal variation of these pesticides. The presence of 11 pesticides was determined. Imazalil, picloram, and malathion the pesticides with the highest concentrations; emamectin, λ-cyhalothrin, methomyl, and picloram were present in all samples. Emamectin was the only pesticide that presented significant differences concerning the temporality of the samplings, presenting higher concentrations in the wet season. Molinate concentrations showed significant differences concerning the location of the sampling sections in the basin; the lower part of the basin presented higher concentrations. The distribution of the populations of L. longicaudis in the Ayuquila-Armería basin does not respond to the degree of contamination by pesticides in surface waters or to the proximity to agricultural activities, and this in places with evident chemical and organic contamination and human presence. The use of otter feces for pesticide monitoring is an accepted non-invasive method to assess the degree of exposure and can be used to determine sites with pollution problems.

Seasonal Urinary Levels of Glyphosate in Children From Agricultural Communities.

BACKGROUND: Glyphosate is one of the most commonly used pesticides in agricultural activities worldwide. For the last 20 years, its use has increased rapidly becoming a public health concern. The IARC classified glyphosate as probably carcinogenic; however, the reported evidence is not enough to establish a statement. OBJECTIVE: This work aimed to measure glyphosate levels in the urine of children from a single rural community in an endemic region of chronic kidney disease and malnutrition. METHODS: A cross-sectional study was carried out in a rural community in western Mexico. The study included 95 children between the ages of 6 and 16. A urine sample (first-morning spot) was obtained from children and processed to measure glyphosate levels using high-performance liquid chromatography coupled with tandem mass spectrometry. RESULTS: All samples tested positive for glyphosate levels. Urine glyphosate levels were related to the season and the age of the children. CONCLUSION: Glyphosate is present in children of all ages in the community even if they were not in direct contact with it. No toxicity cases were reported, nor were there other health problems related to glyphosate. However, more long-term studies should be done that provide a statement regarding the harmful effects that glyphosate has on public health.

Leaching of Metals from e-Waste: From Its Thermodynamic Analysis and Design to Its Implementation and Optimization.

The aim of this study is to design and develop an efficient leaching process based on a fundamental and theoretical thermodynamic analysis and the optimization of the operation parameters via the response surface methodology (RSM). Using this methodology, the design of a leaching process for the recovery of copper, silver, and lead from highly metal-concentrated fractions of e-waste is presented. Thermodynamic predictions were performed through the construction and analysis of Pourbaix diagrams for the specific conditions of the leaching system. From this analysis, it was possible to determine the values of potential (E vs NHE) and pH at which the leaching reactions occur spontaneously. Additionally, RSM was useful to deduce a quadratic semiempirical model that predicts the copper leaching efficiencies as a function of two parameters involved in the leaching procedure, the stirring speed and the solid/liquid ratio, by which the response variable, the leaching efficiency, can be optimized.

Erratum: Sierra-Diaz, E.; Celis-de la Rosa, A.J.; Lozano-Kasten, F.; Trasande, L.; Peregrina-Lucano, A.A.; Sandoval-Pinto, E.; Gonzalez-Chavez, H. Urinary Pesticide Levels in Children and Adolescents Residing in Two Agricultural Communities in Mexico. Int. J. Environ. Res. Public Health 2019, 16, 562.

The authors would like to update some important data in the manuscript. In Table 4, the pesticide means were reported in µg/mL, which is incorrect. The correct units are ng/mL (nanograms/milliliter). The same typographical inaccuracy applies for data in the fourth paragraph of the discussion (with minimal values of 0.0020 µg/mL and maximal values of 2.63 µg/mL), where the correct units are also ng/mL [1]. [...].

Urinary Pesticide Levels in Children and Adolescents Residing in Two Agricultural Communities in Mexico.

The use of pesticides in agricultural activities has increased significantly during the last decades. Several studies have reported the health damage that results from exposure to pesticides. In Mexico, hundreds of communities depend economically on agricultural activities. The participation of minors in this type of activity and their exposure to pesticides represents a potential public health problem. A cross-sectional study was conducted, in which urine samples (first-morning urine) were taken from children under 15 years of age in both communities. A total of 281 urine samples obtained in both communities were processed for the determination of pesticides with high-performance liquid chromatography together with tandem mass spectrometry. In 100% of the samples, at least two pesticides of the 17 reported in the total samples were detected. The presence of malathion, metoxuron, and glyphosate was remarkable in more than 70% of the cases. Substantial differences were detected regarding the other compounds. It is necessary to carry out long-term studies to determine the damage to health resulting from this constant exposure and to inform the health authorities about the problem in order to implement preventive measures.