Biological remediation treatments improve the health of a mixed contaminated soil before significantly reducing contaminant levels.

The remediation of mixed contaminated soil is challenging as it often requires actions to minimize metal-induced risks while degrading organic contaminants. Here, the effectiveness of different bioremediation strategies, namely, rhizoremediation with native plant species, mycoremediation with Pleurotus ostreatus spent mushroom substrate, and biostimulation with organic by-products (i.e., composted sewage sludge and spent mushroom substrate), for the recovery of a mixed contaminated soil from an abandoned gravel pit was studied. The combination of biostimulation and rhizoremediation led to the most significant increase in soil health, according to microbial indicator values. The application of composted sewage sludge led to the highest reduction in anthracene and polychlorinated biphenyls concentrations. None of the strategies managed to decrease contamination levels below regulatory limits, but they did enhance soil health. It was concluded that the biological remediation treatments improved soil functioning in a short time, before the concentration of soil contaminants was significantly reduced.

Mycorrhizal-Assisted Phytoremediation and Intercropping Strategies Improved the Health of Contaminated Soil in a Peri-Urban Area.

Soils of abandoned and vacant lands in the periphery of cities are frequently subjected to illegal dumping and can undergo degradation processes such as depletion of organic matter and nutrients, reduced biodiversity, and the presence of contaminants, which may exert an intense abiotic stress on biological communities. Mycorrhizal-assisted phytoremediation and intercropping strategies are highly suitable options for remediation of these sites. A two-year field experiment was conducted at a peri-urban site contaminated with petroleum hydrocarbons and polychlorinated biphenyls, to assess the effects of plant growth (spontaneous plant species, Medicago sativa, and Populus × canadensis, alone vs. intercropped) and inoculation of a commercial arbuscular mycorrhizal and ectomycorrhizal inoculum. Contaminant degradation, plant performance, and biodiversity, as well as a variety of microbial indicators of soil health (microbial biomass, activity, and diversity parameters) were determined. The rhizosphere bacterial and fungal microbiomes were assessed by measuring the structural diversity and composition via amplicon sequencing. Establishment of spontaneous vegetation led to greater plant and soil microbial diversity. Intercropping enhanced the activity of soil enzymes involved in nutrient cycling. The mycorrhizal treatment was a key contributor to the establishment of intercropping with poplar and alfalfa. Inoculated and poplar-alfalfa intercropped soils had a higher microbial abundance than soils colonized by spontaneous vegetation. Our study provided evidence of the potential of mycorrhizal-assisted phytoremediation and intercropping strategies to improve soil health in degraded peri-urban areas.

Efectividad de la asepsia con cloruro de benzalconio vs. el uso de agua y jabón en la prevención de la onfalitis neonatal. Hospital de Apoyo José Alfredo Mendoza Olavarría. Tumbes 2006 / Effectiveness of aseptic benzalkonium chloride vs. using soap and water in preventing neonatal omphalitis. Hospital de Apoyo Jose Alfredo Mendoza Olavarria. Tumbes 2006

Objetivo: demostrar que la asepsia con cloruro de benzalconio es más efectiva que el uso de agua y jabón en la prevención de la onfalitis neonatal en el Hospital de Apoyo JAMO de Tumbes durante el período enero a abril del 2006. Métodos: estudio descriptivo, prospectivo, longitudinal y comparativo. Se incluyeron neonatos de ambos sexos, a término, de parto eutócico y cesárea, y se utilizó el muestreo no probabilístico de tipo accidental. El diseño fue de dos grupos, con sujetos aleatorizado y sólo con posprueba. Para la comparación de la efectividad del cloruro de benzalconio vs. El uso de agua y jabón se utilizaron las pruebas paramétricas Chi Cuadrado y t de Student. Resultados: ingresaron al estudio 84 neonatos; la mitad recibió asepsia con cloruro de benzalconio y el resto, con agua y jabón. Del total de la muestra, 82 neonatos no presentaron signos de onfalitis y sólo se evidenciaron dos casos, uno con cada tipo de antiséptico (2.4%). Sin embargo, no se encontró una relación significativa (p>0.05) entre la presencia de signos inflamatorios y el producto empleado para la asepsia. Asimismo, del total de la muestra (84 neonatos), cuatro presentaron la caída del cordón umbilical entre 3er y 5to día (uno con cloruro de benzalconio y tres con agua y jabón) mientras que a 78 neonatos se les desprendió el cordón umbilical entre el 6° y el 9° día y a dos neonatos pasados los diez días (un caso para cada antiséptico usado). Las pruebas estadísticas no mostraron relación significativa (p>0.05) entre el tiempo de caída del cordón umbilical y el tipo de antiséptico usado. Encontramos que al tasa de prevalencia de onfalitis fue de 2.38% y el tiempo promedio de aparición de los signos de onfalitis fue de cuatro días luego de utilizar ambos antisépticos.