Toxicología ambiental y analítica

Esta investigación se realizó para determinar la productividad, las vitaminas y la concentración de metales pesados ??de los cuerpos fructíferos de Pleurotus ostreatus (Jacq: Fr) Kumm. cultivados en diferentes troncos de madera. El cultivo de micelio puro de P. ostreatus se multiplicó asépticamente por transferencia de grano a grano utilizando granos de sorgo. El micelio completamente colonizado se utilizó para inocular troncos de Mangifera indica , Dacryodes edulis y Treculia africana y se incubó en la oscuridad a 27 °C ± 2 M. Los primordios del cuerpo fructífero se observaron primero en D. edulis seguido de T. africana y por último en troncos de M. indica después de 11, 13 y 15 días respectivamente. El sustrato de troncos de M. indica dio el rendimiento más alto (245,8100 g/kg) de cuerpos fructíferos de P. ostreatus entre otros sustratos de troncos. Los contenidos de vitaminas fueron significativamente más altos en P. ostreatus cultivado en troncos de D. edulis , mientras que P. ostreatus cultivado en todos los sustratos de troncos acumuló cobre más que todos los demás metales pesados ??analizados. Tanto los contenidos de vitaminas como de metales pesados ??de P. ostreatus en varios sustratos de troncos fueron significativamente diferentes p<0,05. El cultivo de P. ostreatus en troncos de M. indica, especialmente antes de que se utilicen como leña, ayudará a aumentar la provisión de alimentos.

Para estudiar las características de los elementos inorgánicos, las especies de carbono, los HAP de exposición y los elementos de riesgo para la salud a PM2.5 para ciclistas urbanos en Tianjin. La exposición a PM2.5 en muestras de ciclismo se recogió durante el verano en Tianjin. Se discutió el riesgo no cancerígeno y el riesgo cancerígeno de la exposición personal al metal pesado en PM2.5. La concentración de masa de exposición personal promedio de PM2.5 es 340,63 μg/m3 en un día laborable, 281,25 μg/m3 en el fin de semana para ciclistas. El análisis del factor de enriquecimiento mostró que Pb, Zn, Ni y Cu exhibieron una contaminación intensa o extrema, lo que indica la influencia de fuentes antropogénicas, pero K, Ca, Mg, Mn y Fe se enriquecieron mínimamente y fueron influenciados principalmente por fuentes de la corteza o fuentes antropogénicas menores. El SOC promedio es 23,33 μg/m3. La proporción de SOC es 34,78% en OC. Los HAP en PM2.5, compuestos de 2 y 3 anillos fueron predominantes, y NAP, PHE y ACY representaron el 25 %, 48 % y 9 % de los HAP para la exposición personal de ciclistas, respectivamente. En cuanto a los efectos no cancerígenos, los valores del índice de riesgo para todos los metales estudiados fueron inferiores al nivel seguro de 1 para ciclistas. El riesgo cancerígeno para Cr y Ni estuvo por debajo del nivel aceptable (10-4~10-6). El presente estudio demostró los elementos que representan un riesgo para la salud en los ciclistas urbanos. El estudio puede proporcionar una base científica para proteger la salud y la seguridad de los ciclistas.

El gas licuado de petróleo (GLP) se utiliza ampliamente como combustible en hogares y vehículos en cilindros de gas comprimido. Anteriormente se habían publicado algunos informes de toxicidad por inhalación de gas que causaban diferentes síntomas, desde un simple dolor de cabeza y mareos hasta coma y muerte. En este informe, se explica el estado de dos niños, una niña de 5 años y su hermano de 2 años, que sufrieron convulsiones y un nivel reducido de conciencia después de jugar con y abrir la válvula de gas de una cocina portátil a gas.

Se desarrolló un método de generación atómica de hidruro por inyección de flujo (FI-HG-AAS) para la determinación de arsénico en materiales de referencia certificados después de la digestión húmeda abierta de muestras. Se optimizaron los pasos del método y se determinaron los parámetros analíticos y estadísticos del método (límite de detección 1 μg/kg-1, límite de cuantificación 3 μg/kg-1). La precisión del método se evaluó utilizando los materiales de referencia GBW10043 (arroz), GBW100052 (té verde), T0770 (harina de soja), NCS-ZC 73013 (espinaca), NCS-ZC 73015 (leche en polvo).

The present study explored the removal of toxic Cr(VI) ions by MnO2 coated polyaniline nanofibers (MPNF) adsorbent by batch mode technique. The MnO2 coated polyaniline nanofibers were synthesized by in-situ oxidative polymerization of polyaniline by rapid mixing technique and were employed for the removal of Cr(VI) ions from aqueous solution. The synthesized adsorbent was characterized by various techniques to elucidate the structure, composition, and morphology. The effects of pH, initial Cr(VI) concentration, adsorbent dose, temperature and operating time on adsorption were investigated. The maximum adsorption removal efficiency was observed at low pH i.e., 1.0. Spectrophotometric method was used to examine the Cr(VI) concentration in the filtrate after batch adsorption studies. The equilibrium adsorption capacity and adsorption kinetics followed Freundlich isotherm and pseudo-second-order respectively, with a capacity of 39.3 mg/g. The thermodynamic study parameters like: ΔH°, ΔS° and ΔG° revealed that the adsorption process is spontaneous and endothermic at high temperature.

Natural and anthropogenic factors affect soil pollution which significantly reduces environmental quality. In this study, six hazardous elements namely Chromium (Cr), Nickel (Ni), Arsenic (As), Cadmium (Cd) and Lead (Pb), in 12 different sampling sites around brick kiln vicinity from Bangladesh were assessed. The ranges of Cr, Ni, Cu, As, Cd and Pb in studied soils were 0.77–21.71, 4.74– 27.67, 3.08–38.56, 2.51–28.44, 1.03–8.06 and 2.23–18.31 mg/kg, respectively. Presence of these hazardous elements in soils is indicating a potential risk to the environment. Certain indices, including the enrichment factor (EF), pollution load index (PLI) and contamination factor (Ci f), geoaccumulation index (Igeo), toxic unit analysis and principal component analysis (PCA) were used to assess the ecological risk posed by hazardous elements in soils. The Ci f values of As (15.34) and Cd (37.89) revealed that the examined soils were strongly impacted by As and Cd where Pollution load index in As (1.01) and Cd (2.61) indicating progressive deterioration of soil due to metal contamination. In view of the above results, soils from all sampling sites showed considerable to very high potential ecological risk.

Objective: In order to explore the impacts of environmental hormones (EHs) on plants, the relationship between EHs pollutants and Spinacia oleracea HSP70-9 expression was studied in this paper. The researchers studying HSP70 have primarily investigated high temperature stress, low temperature stress, water stress and other environmental factors, such as heavy metals, wind stress, salt stress. However, as a type of environmental pollutant, EHs may affect the growth and development of plants.
Methods: Two typical EHs, PAEs (phthalates esters) and BPA (bisphenol A), were selected for the study. RT-qPCR was used to study HSP70-9 expression at the transcriptional level under single and combined pollution conditions in spinach seedlings.
Results: The result of the present study showed that, the spinach HSP70-9 expression is downregulated with single and combined treatments of EHs.
Conclusion: The conclusion is that BPA and PAEs had certain effects on the expression of HSP70-9 in spinach.

The study was conducted in Gozamen district of East Gojam Zone of the Amhara region to assess the major feed resources, the grazing land condition, the floristic composition, and biomass yields of herbaceous species to generate baseline information which can be used for future management of grazing land resources and to identify feed constraints in the area. The survey data was collected by interviewing a total of 120 households by random selection of two rural kebeles from three altitudes (high, mid and low). To assess grazing land condition, the district was stratified into three altitudes (high, mid and low altitudes). From each altitude, communal and enclosed grazing areas were selected randomly. From each altitude 8 composites and 12 composites from enclosed and 12 composites from communal grazing for herbaceous vegetation and 4 transects from each altitude of communal grazing were selected. Thus, a total of 72 quadrats were used for herbaceous and 12 transects for woody species. For the natural pasture condition assessment, analyses of variance (ANOVA) were carried out by the General Linear Model (GLM) procedure of SAS. Mean separation was tested using the least significant difference. The main feed resources to the livestock in all altitudes were natural pasture, crop residues and stubble grazing. During dry season, crop residues was the first livestock feed source followed by natural pasture in all altitudes. However, during wet season, natural pasture was the first livestock feed source followed by crop resides in all altitudes. In terms of dry matter (DM) crop residues contributed the highest proportion (66.7%) of the total feed sources. The DM obtained from crop residues significantly varied (P<0.05) among the altitudes. The total annual estimated available feed supply to maintain the livestock in the area satisfied only 79.4%. The conservation of feed resources in the form of hay in high, mid and low altitudes was 38.5, 80, and 22.5%, respectively. But, none of the respondents used silage in the study area due to lack of knowledge how to make it. In the district, a total of 21 herbaceous species were identified, from these 57, 24 and 19% were grasses, legumes and other species, respectively. Based on dry matter of biomass, Medicago polymorpha in high and mid altitudes and Eleusine floccifolia in low altitude were the dominant species. Altitude and grazing have effects on grazing land conditions and biomass production. The average dry matter yield of grasses, legumes and total biomass had a significant difference among altitudes in enclosed and communal grazing areas. The average dry matter yield of grasses, legumes, and total biomass were higher in enclosed area than communal grazing areas in all altitudes. There were a significant (P<0.01) interaction of altitude and grazing on biomass and species composition. There was positive correlation of species composition, grass species composition and basal cover with biomass. Crop residues and natural pastures are the major feed resources in dry and wet seasons, respectively. The total annual dry matter does not meet the total livestock requirement per annum in district. Further research and development work is recommended to alleviate feed shortage through different options such as development of improved forages and alternative means of crop residue utilization and conservation of feed in the form hay and crop residues.

The Present study was aimed to estimate and investigate some physico-chemical parameters of Dal Lake of Kashmir, India. During the present study water samples from five basins were collected and analyzed for the physicochemical properties. Analysis showed a great variation in water quality among the different basins. Much polluted basins i.e., Telebal and Jogilankar are having deteriorated water qualities and possible reason for this could be the increasing eutrophication resulting from agricultural practices in the nearby catchment area or tourism activity.

This study indicated the status of drinking water containing two heavy metals (Zinc and Lead) in case of the areas adjacent to tannery industries located in Dhaka city as well as outside areas. The drinking water was collected from both tube wells and taps, and then metals were determined using Flame AAS. Both Zinc and Lead content was found highest in the tap water of the area of tanneries named Hazaribagh expressing as 54 ppb and 200 ppb respectively. But in tube well water of this area, the amount of Zinc ranges from 31 ppb to 50 ppb but the Lead content was found as nil. Again areas far from tanneries, the lead content was found 138 ppb as highest.

This study was carried out to determine the potential occurrence of pesticide residues in the milk of buffalo and women, which exists in vegetables and fruits farming community in Rosetta region Northern of Delta, Egypt. Milk samples were analyzed by gas chromatography-electron capture detector. Halogenated pesticides were selected includes: 1- Organochlorines; Hexachlorocyclohexane isomers (a, ß, ?-HCHs), dichlorodiphenyltrichloroethane (p, p' – DDT) and its degradates; p, p'-DDD and DDE, and cyclodiene compounds; Aldrin, dieldrin and endrin. 2- Organophosphorous pesticides; Chlorpyrifos, chlorpyrifos methyl and profenofos. 3- Pyrethroids; Cypermethrin and lambda-cyhalothrin. The tested organochlorine pesticides were detected in most of the samples analyzed at lower frequencies and levels ranged from 2.38 to 3.57 µg/kg in buffalo than of human milk (2.4-5.78 µg/kg). Whereas organophosphorous and pyrethroids found at high predominance of frequencies among all the tested compounds in the buffalo milk than in human milk analyzed. Generally, all samples were positive for at least one of the pesticides; Chlorpyrifos, chlorpyrifos, methyl, profenfos or cypermethrin with mean levels ranged from 1.9 to 5.14 µg/kg of the two milk types, except lambdacyhalothrin at below detection limit in all human breast milk samples. Statistically, significant difference and correlation of organochlorines levels (but no significant difference or correlation for organophosphorous and pyrethroids) were found between the two types of milk investigated. The data available for estimation of daily intakes (ADIs) and extraneous and maximum residue limits (ERLs & MRLs) revealed that these compounds were found to be lower than the safety thresholds level. Results of this study indicated that in spite of the banning much of organochlorine pesticides (rather than the currently applied (e.g., organophosphorous and pyrethroid pesticides), still contaminating the food stuffs, particularly milk.