Declaración de Cuernavaca.

Los Institutos Nacionales de Salud (INS) miembros de la Red Regional Latinoamericana de la Asociación Internacional de Institutos Nacionales de Salud Pública, reunidos en forma presencial en la sede del Instituto Nacional de Salud Pública de México, en la Ciudad de Cuernavaca, los días 5 al 7 de octubre de 2022, contando con la participación de los directores o representantes de los INS de (...).

Efectividad de los bloqueadores solares en la prevención de las lesiones de piel no oncológicas / Effectiveness of sunscreens in the prevention of non-oncological skin lesions

ANTECEDENTES: El cáncer de piel es una de las neoplasias de alta importancia en salud pública, no solo por el incremento progresivo de su frecuencia, sino también por su importante repercusión a nivel de moratlidad, morbilidad y el subsecuente impacto económico en la sociedad. Asimismo, ha sido clasificado en dos grandes grupos: en melanoma y no melanoma, este último conformado por los carcinomas basocelular y espinocelular. Se han identificado una serie de factores de riesgo; como la exposición solar excesiva, los tipos de piel I y II, los cambios en un lunar previo, la tendencia a presentar pecas, la presencia de gran número de lunares, la inmunosupresión y antecedente personal o familiar de cáncer de piel, entre otras. En ese sentido, se han propuesto diversas actividades de prevención primaria, que incluyen campañas educativas dirigidas a disminuir o evitar la exposición solar e incrementar el uso de bloqueadores solares; así como actividades de prevención secundaria en búsqueda de un diagnóstico temprano por parte de los profesionales de la salud. Es importante, en dicho contexto que las políticas públicas sean informadas en la mejor evidencia disponible. Más aun, cuando existe controversia respecto al impacto de dichas intervenciones sobre el desarrollo de cáncer de piel. OBJETIVO: Evaluar la efectividad del uso de los bloqueadores solares en la prevención del melanoma maligno, carcinoma basocelular y carcinoma escamoso en la población general. METODOLOGÍA: Se realizó una sinopsis de revisiones sistemáticas (RS) siguiendo el modelo propuesto por Haynes et al. La búsqueda se realizó en MEDLINE y EMBASE hasta el 18 de enero 2013. Dos revisores independientes seleccionaron, después de la lectura de títulos y resúmenes, aquellos que cumplían con los criterios de inclusión y con el objetivo de la búsqueda. Después de la lectura en extenso, los dos revisores selecionaron los estudios que permanecerían en la sinopsis y extrajeron la información necesaria. En caso de haber discrepancias, un tercer investigador cumplió un rol dirimente. Se empleó la herramienta AMSTAR para la evaluación de la calidad de las RS. RESULTADOS: Se identificaron 38 artículos en MEDLINE y 23 en EMBASE. De estos, se seleccionaron 11 artículos, tras la evaluación de concordancia y la lectura de resúmenes y títulos. Posteriormente se realizó una lectura a texto completo, en la cual se excluyeron siete publicaciones debido a que correspondían a revisiones narrativas, a un modelo matemático de predicción de casos evitados o eran de baja calidad. No se encontró evidencia proveniente de revisiones sistemátcias de alta y media calidad sobre la asociación entre el uso de bloqueadores solares y el carcinoma espinocelular ni basocelular en población general. El uso de bloqueadores solares está asociado a un menor riesgo de carcinoma espinocelular en pacientes que tuvieron antecedentes de lesiones en piel inducidas por el sol, cuando la exposición solar no era intencional, En el análisis global no se encontró asociación entre el uso de bloqueadores y el riesgo de melanoma. En el análisis por subgrupos una de las revisiones encontró un leve efecto protector de los bloqueadores solares (OR: 0,76; IC95% [0,65-0,90]), cuando sólo se incluyeron en el análisis estudios que consideraban variables como la sensibilidad solar de la piel y antecedentes de quemaduras solares. Por otro lado, otra revisión encontró un mayor riesgo de melanoma en pacientes de países alejados del Ecuador (a más de 40° latitud) que usaban bloqueadores (OR: 1,6; IC95% [1,3­1,9]). CONCLUSIÓN: El uso de bloqueadores solares no es efectivo para la prevención de cáncer de piel en población general; pero es efectivo en la prevención de melanoma y carcinoma espinocelular en poblaciones específicas.(AU)

Assessment of Argentinean Patagonia pollution: PBDEs, OCPs and PCBs in different matrices from the Río Negro basin.

This work reports the occurrence and distribution of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in soil, sediment, suspended particle matter (SPM), streamwater and macrophytes, along the Río Negro basin, Argentinean Patagonia. The clear predominance of OCPs among all matrices indicates the impact of agriculture on the watershed. The highest levels were found for pp'-DDE which represented up to 95% in agricultural soils (42.0-1.27x10(3) ng/g d.w) from the Upper Valley (upstream), where long and historical intensive fruit cultures have been settled and represent a hot spot of legacy pesticides for the environment. The insecticide endosulfan, currently in use, was also found in all matrices. Levels ranged between 0.3 and 708.0 ng/g d.w, being the highest concentrations those of SPM from the Middle Valley, just before the delta area, where pesticides would be retained leading to lower concentrations as was observed downstream. PCB (#153, 138, 110, 101) and PBDE (BDE-47) levels were directly related with the presence of hydroelectric power plants, dams and dumping sites, mainly settled in the Upper Valley (0.8 ng/g and 15.1 ng/g d.w for PBDEs and PCBs, respectively). Although there was a decreasing gradient of these pollutant concentrations through the river flow, downstream urban areas enhanced PCB concentrations in the aquatic environment. More efforts and monitoring programs are highly required to control and reduce soil erosion in order to prevent the availability of forbidden pollutants in the environment.

Endosulfan induces oxidative stress and changes on detoxication enzymes in the aquatic macrophyte Myriophyllum quitense.

Endosulfan (1) is a chlorinated insecticide still in use in both developed and emerging countries. Although its toxicity on animals has been studied in the last years, scarce information is available on its effects on plants. In this study, we exposed the aquatic macrophyte Myriophyllum quitense to environmentally relevant concentrations of endosulfan (microg/L) (1) for a short time, simulating exposures that might occur after either accidental spills or toxic run-off from agricultural areas. The main goal was to evaluate changes in both detoxication and antioxidant enzymatic systems of this plant upon exposure to endosulfan (1). Thus, we measured the activities of catalase (CAT), soluble and membrane associated glutathione-S-transferases (s- and m-GSTs) and glutathione reductase (GR), as well as the hydrogen peroxide (H2O2) content. Results showed that endosulfan (1) exerts oxidative stress on M. quitense, which was evidenced by the increase of CAT activity and the H2O2 content in exposed plants. At 5 microg/L endosulfan (1), we found a generalized induction of activities of tested enzymes, indicating that this xenobiotic activates the protection system of this plant, increasing its capacity to scavenge reactive oxygen species. On the other hand, we did not find significant changes at 0.02 microg/L endosulfan (1), which is the maximal concentration allowed for freshwater. We conclude that runoff events, which can produce significant amounts of endosulfan (1) in aquatic environments during short time, can result in oxidative stress on M. quitense, and probably on similar macrophytes.

Genotoxicity evaluation of the insecticide endosulfan in the wetland macrophyte Bidens laevis L.

The frequency of micronuclei (MN) and chromosome aberrations in anaphase-telophase (CAAT) was determined in root tips of the wetland macrophyte Bidens laevis exposed to environmentally relevant concentrations of endosulfan (0.01, 0.02, 0.5 and 5microg/L) for 48h. MN frequency varied from 0 in negative controls and plants exposed to 0.01microg/L endosulfan to 0-3 in plants exposed to 5microg/L. Moreover, a significant concentration-dependent increase of CAAT was observed. The higher proportion of laggards and vagrand chromosomes observed at 5microg/L would indicate that endosulfan interacts with the spindle interrupting normal chromosome migration. Endosulfan resulted genotoxic to B. laevis, a species of potential value for bioassays and in situ monitoring of environmental contamination by pesticides.

Field accumulative behavior of organochlorine pesticides. The role of crabs and sediment characteristics in coastal environments.

The influence of intertidal crab beds on the concentrations of organochlorine (OC) pesticides in sediment was studied in two different coastal environments in Argentina. Samples of male burrowing crabs (Chasmagnathus granulatus) were collected for this study. Our field data showed lower bioaccumulation of OC pesticides in crabs from sediments with a higher total organic carbon (TOC) and higher clay content. Thus, concentrations in crabs depend on the physico-chemical characteristics of the sediment where they live more than on the OC pesticide concentrations in the environment. The distribution patterns in sediment from inside and outside crab burrows were similar for both coastal areas being HCHs > or = gamma-chlordane > p,p'-DDE for San Antonio Bay (SAO), and HCHs > p,p'-DDE > or = gamma-chlordane for Mar Chiquita (MCh) coastal lagoon. OC pesticide concentrations in sediment were significantly lower inside than outside crab burrows, irrespective of the sediment physico-chemical characteristics due to the bioturbation activity of C. granulatus.

Evaluation of conventionally and organically produced vegetables for high lipophilic organochlorine pesticide (OCP) residues.

The occurrence and distribution of highly hydrophobic organochlorine pesticide (OCP) in vegetables cultivated under organic and conventional conditions were evaluated. OCP residues in aerial and subterranean tissues of two varieties of lettuce and chard together with the soil where they grown were GC-ECD analyzed. SigmaDDTs>SigmaChlordane>SigmaHeptachlor>SigmaAldrins was the OCP distribution pattern in all samples. Conventional soils had higher OCP residues than organic one, even though levels were bellow 5 ng/g dry weight, indicative of low polluted agricultural environments. Vegetables accumulated OCP efficiently with residue levels 4x to 45x fold greater than those of soils. OCP tissue-dependent distribution was found to be upon the physicochemical characteristics of the pollutants (Koa and Kow). Lettuce showed a high variability in pesticide uptake regarding varieties and tillage practices. In spite of analyzed pesticides are banned or restricted, edible tissues of vegetables from both farms showed detectable residues of these compounds even though at levels below the allowed by the Codex Alimentarius. Thus, environmental conditions like presence or absence of trees, hedgerows or nearby to conventional farms influence on OCP occurrence and levels in vegetables organically grown.

Land-based sources of marine pollution: organochlorine pesticides in stream systems.

BACKGROUND: Organochlorine pesticides (OCPs) have been dispersed ubiquitously in the environment. Bottom sediments act as sinks for these compounds and their concentrations often reflect the degree of anthropogenic pollution. This study was designed to evaluate the occurrence and distribution of OCPs in superficial streambed sediments and their relation to land use in two creeks that contribute to the coastal pollution of the southeastern region of Argentina. METHODS: Sampling sites were selected by a combination of land use and stream type. Las Brusquitas creek, which passes through vast agricultural areas, and La Tapera creek which originates in a natural wetland and passes through horticultural farming and urban areas. OCPs quantification was carried out by GC-ECD. RESULTS AND DISCUSSION: Results showed similar total OCP concentrations in sediments from both creeks in the range of 6-25 ng/g dry wt. However, when OCPs were expressed in ng/g total organic carbon (TOC), La Tapera creek presented 4-fold higher total levels as a consequence of a higher OCP input during the recent past in that watershed. La Tapera outfall showed 4-fold higher levels than that seen in Las Brusquitas, although both values were below the sediment quality criteria demanded to protect wildlife. Sigmaendosulfans, sigmaDDTs and sigmachlordanes were the main OCP group in all samples, with Endosulfan sulfate being the most frequent and abundant compound. The predominance of metabolites with respect to parent compounds suggests a contamination mainly by runoff from aged and weathered agricultural soils. CONCLUSIONS: Despite OCPs being banned, they still exist in creek sediments from the studied region, representing continuous contributions of land-based source contaminants to the marine environment. OUTLOOK: Future research on OCP levels in suspended sediments is recommended in order to determine the total OCP concentrations in the selected stream systems.

Organochlorine pesticides sequestered in the aquatic macrophyte Schoenoplectus californicus (C.A. Meyer) Soják from a shallow lake in Argentina.

This study was conducted in Los Padres Lake from Argentina in order to assess the ability of Schoenoplectus californicus to bioconcentrate organochlorine pesticides (OCPs). Bulrush tissues, superficial and near root sediments were collected from the input and the output creek areas. OCP analyses were carried out by GC-ECD. Samples from the input creek area showed the higher OCP levels as a result of contaminants washed down from upstream agricultural fields. Bulrush roots accumulated the highest concentrations of pollutants (30.2-45.7ngg(-1) dry weight). DDTs and chlordanes predominated in sediments and roots besides endosulfan sulfate. The sediments constitute the main source for these OCPs partitioning to bulrush. Stems mainly exposed to water column accumulated preferentially the less hydrophobic pesticides, such as HCHs and endosulfans. We have confirmed the important role of S. californicus in the contaminant removal from sediments. Therefore, this macrophyte can be used as a tool for field studies of OCP pollution monitoring and remediation.

The role of burrowing beds and burrows of the SW Atlantic intertidal crab Chasmagnathus granulata in trapping organochlorine pesticides.

The effect of crab beds and bioturbation activity of the SW Atlantic intertidal crab Chasmagnathus granulata on the organochlorine pesticide (OCP) concentrations in Bahía Blanca estuary, Argentina were studied. Total OCP concentration was significantly lower inside than outside the crab burrows. Nevertheless, the concentrations from outside the crab beds were lower than from outside crab burrows, which indicated that crab beds act as sinks of sediment-bound OCP due to the bioturbation activities of the crabs. The same distribution patterns were found in all sediments as well as in crabs, being cyclodienes>HCHs>DDTs, although large amounts of metabolites rather than the respective parental were found in the organism showing the capacity of C. granulata for metabolising parental compounds. These more water-soluble compounds are excreted by the faeces and finally removed by tidal flushing to the sea. Our results suggest that crabs when present play a role in the distribution of sediment-bound OCP and the crab beds are modifiers of the dynamic of organic pollutants in estuarine areas.

Organochlorine pesticide residues in leek (Allium porrum) crops grown on untreated soils from an agricultural environment.

Leek (Allium porrum) plants from organic farming were harvested at 15, 59, and 210 days after seed germination. Organochlorine pesticide (OCP) levels were quantified by GC-ECD in vegetative tissues (roots and aerial), bulk soil and rhizosphere. Leek plant bioaccumulate OCPs efficiently in their aerial and root tissues and alter the concentration of the soil where they are grown. OCPs distribution pattern of bulk soil was endosulfans > DDTs > dieldrin, while it was endosulfans > HCHs > DDTs in leek tissues. There were statistically significant declines in DDTs, chlordane, dieldrin, and heptachlor in the rhizosphere, indicating that recalcitrant residues of OCPs may be removed from contaminated soil using leek crops under normal growing conditions. The DDE/DDT and alpha-/gamma-HCH ratios of < 1 would indicate recent inputs of DDT and lindane in the environment. The occurrence of OCPs in this farm could be the result of atmospheric deposition and/or surface runoff of these pesticides.

Dynamics of organochlorine pesticides in soils from a southeastern region of Argentina.

Monitoring of organochlorine pesticides (OCPs) was carried out to identify and quantify the contribution of point and nonpoint sources to the total OCP flux in a southeastern region of Argentina. Natural, recreational, and agricultural soils located in the surrounding of a lagoon were analyzed by gas chromatography with electron-capture detector. Physical and chemical characteristics (texture, humidity, and organic matter content) were determined at different depths (0-15 cm, 15-30 cm, and 45-55 cm). The pattern of OCP distribution was similar in all soil sampled, with DDT and metabolites > hexachlorocyclohexanes (HCHs) > heptachlor > chlordanes. The highest values of OCPs (656.1 ng/g dry wt) were found in the surface natural soil despite its never having received direct OCP application. This would be mainly due to the high organic matter content of the surface natural soils as well as its topographic position (highland hills), with main winds arriving from agricultural areas. Microorganism abundance and edaphic biota in the upper layer would justify the high levels of metabolites found. The agricultural soil (intensive tillage) also showed the highest OCP values (30.19 ng/g dry wt) in the surface horizon. Because of management practices, volatilization could have been one of the major causes of pesticide loss from this target area. Recreational soil showed the lowest OCP levels in the surface layer because of weathering that occurs when the nearby lagoon floods this zone. Our results show that, although most of these pesticides are banned, they are present in these soils and the atmospheric transport and deposition would be the major processes for distributing OCPs from target to natural areas.

Occurrence and distribution of organochlorine pesticides (OCPs) in tomato (Lycopersicon esculentum) crops from organic production.

Organochlorine pesticides (OCPs) were quantified by GC-ECD in tomato (Lycopersicon esculentum) during a vegetation period. Plants were harvested at 15, 60, and 151 days after seed germination. Leaves, stem, roots, and fruit (peel and flesh) were analyzed separately. The results showed that tomato plants were able to accumulate OCPs from soils, and a trend to reach the equilibrium among tissues at mature stages was also observed. Endosulfans comprised the main OCP group, probably due to its spray during summer months in the surrounding areas. Banned pesticides such as DDTs, heptachlor, and dieldrin were found. OCPs levels in the fruit were below the maximum residues limits (MRL) considered by the Codex Alimentarius. DDE/DDT and alpha-/gamma-HCH ratios of <1 would indicate recent inputs of DDT and lindane in the environment. The occurrence of OCPs in the study farm, where agrochemicals have never been used, is a result of atmospheric deposition of those pesticides.

Polychlorinated biphenyls in different trophic levels from a shallow lake in Argentina.

Polychlorinated biphenyls (PCBs) were determined in a aquatic community from Los Padres Lake, Argentina. Twenty four PCB congeners from tri- to octa-chlorinated isomers were detected and quantified using conventional gas chromatography with electron capture detector (GC-ECD). The aim of this study was to investigate the concentrations of PCBs in freshwater organisms from a shallow lake of Argentina. Stems of bulrush (Schoenoplectus californicus), whole tissues of false loosestrife (Ludwigia sp.) and grass shrimp (Palaemonetes argentinus), and liver, gonads, muscle and mesenteric fat (if present) of fish species (Rhamdia sapo) and (Oligosarcus jenynsi) were analyzed. Two areas were selected to macrophytes sampling: the input area, main PCB source of the lake (Station 1), and the output area, a potential anoxic zone (Station 2). Macrophytes from Station I bioconcentrated higher total PCB levels than Station 2, showing that the former have received PCBs washed down from upstream areas. Penta- and hexa-congeners were enriched relative to other congeners in animal biota and macrophytes from Station 1, consistent with commercial mixture of Aroclor 1254 used in this region. In bulrush from Station 2 a predominance of tri- and tetra-chlorinated congeners was observed. Grass shrimp showed the lowest PCB values among animal biota. PCB concentrations in fish tissues varied with the species and the gonadal development. Mesenteric fat, only present in post-spawning organisms of R. sapo, had the highest values of PCBs relative to other tissues. A clearance of total PCBs in ovaries of post-spawning females of R. sapo was observed, but not in testes. O. jenynsil P. argentinus biomagnification factor (BMF) had a mean value of 18.7. Congeners 44, 52 and 151, showed the highest BMF values, being 64, 66 and 62, respectively. These values would be a consequence of the low depuration rate of 44 and 52 congeners with orthochlorine substitution conducted by O. jenynsi and the high depuration rate of congener 151, which lacks 4 4'- chlorine substitution, carried out by grass shrimp. Although the most of congeners have been biomagnified, they did not clearly displayed a concomitantly increasing with log K(ow).

Agricultural soil as a potential source of input of organochlorine pesticides into a nearby pond.

A study was conducted in the southeastern region of Buenos Aires province, Argentina, to assess an agricultural soil as a potential source of organochlorine (OC) pesticides for the aquatic biota of a nearby pond. We analyzed gamma-HCH (lindane), still in use, and the following banned compounds: DDT, DDE, DDD heptachlor, heptachlor epoxide, aldrin, dieldrin and endrin in soil, bulrush, grass shrimp and fish using gas chromatography with electron capture detection (GC-ECD). Among the OC pesticides, lindane was most dominant in the soil (32.6 ng/g dry wt in the upper and 173.9 ng/g dry wt in the lower horizon) and bulrush (1.9 pg/g lipid). Macrophyte also accumulated high levels of heptachlor epoxide (1.5 pg/g lipid). Heptachlor, although present in the soil, was below the detection limit in all aquatic biota studied. Its primary degradation product, heptachlor epoxide, was found in both soil and biota samples. DDT was found at low levels in the surface soil (6.8 ng/g dry wt), but at higher concentrations in fish (3.6 pg/g lipid), although levels were still below permissible levels for human consumption. Since most of the compounds were found in both soil and aquatic biota, our study suggests that agricultural soil could be an important source for OC pesticides in the nearby pond.