Toxicología ambiental y analítica

It is known that usage of chalk causes dust and exposure to chalk dust can cause health hazards in teachers. But the level of exposure to chalk dust in teachers were not known so far. Hence, present study aimed to investigate the level of exposure to chalk dust in teachers by studying the whole blood concentrations of trace elements (Al, Cr, Mn, Fe, Co, Ni, Si, Pb) that are associated with chalk. ICPMS method was adopted to conduct the trace element concentration in whole blood and due to lack of reference standards, the recovery percentages were analyzed. From the results, it is identified that except Si all the elements are noticed beyond the normal blood limits in teachers. For silicon, there is no normal blood limit. The relation between the trace elemental concentration and socio demographic variables like gender, age, Years of service was also studied. The age and gender did not show significant difference with the trace element concentration. The years of service revealed a positive association with trace element concentrations. The elements like Si (70847 μg/l), Iron (19499 μg/l), Al (1389.9 μg/l) were noticed with elevated concentrations in teachers. The same elements were reported with higher concentrations in past studies that are conducted on trace elements concentration of chalk. Hence, it is proved that the chalk is the prime reason for the elevated concentrations of trace elements in blood and it also concluded that usage of chalk causes health hazards in teachers.

In the present study, we evaluated the DNA damage of freshwater copepod Mesocyclops aspericornis collected from Chembarambakkam, Velachery and Retteri Lake during Premonsoon(PRM) and Post-monsoon (POM) by alkaline comet assay. The highest DNA integrity was observed at Velachery Lake (21.52 ± 0.31 Mean % Tail DNA) followed by Retteri Lake (13.84 ± 0.019 Mean % Tail DNA) during both season, whereas the lowest DNA integrity occurred at Chembarambakkam (0.16 ± 0.14 Mean % Tail) and identified as the reference site. The single cell gel electrophoresis of M. aspericornis clearly showed relatively higher olive tail moment from the contaminated sites Velachery and Retteri Lake (4.66 ± 0.055; 1.42 ± 0.12). During study period we observed the lowest pH and dissolved oxygen levels in the contaminated sites than the reference site. Moreover high level of genotoxic contaminants especially heavy metals (Zn, Cr, Mn, Pd, Ni, Cu, Co) are widespread in all sites, which could be mainly attributed to the high integrity of DNA in freshwater copepod. The results obtained in this study provide an early warning signal of contamination of the freshwater bodies of Chennai by genotoxic contaminants and explore the importance to conservation of those water bodies.

Bioassays were performed on phytoplankton communities from the coastal waters at Grand Isle, Louisiana from February through August 2013 to determine the impact of the water-accommodated fraction of unweathered Macondo well oil on the growth rates and taxonomic composition of the phytoplankton. Pigment analysis indicated that diatoms dominated the natural phytoplankton communities, and with one exception, diatoms were the only class of phytoplankton that grew in control cultures or in artificial seawater amended with the water-accommodated fractions of Macondo well oil at a series of concentrations from 0.1 to 19.2 mg L–1. The growth rates of diatoms were enhanced by roughly 10% at oil concentrations ≤ 0.6 mg L–1 but were reduced by up to 30% at concentrations ≥ 1.0 mg L–1. Ratios of fucoxanthin to chlorophyll a were positively correlated with oil concentrations, an indication that there was some adjustment of the characteristics of the light-harvesting antennae of the diatoms in response to the stress of the oil.

There is no doubt that health issues are extremely important when dealing with the impact of air pollution. Increasingly, society is becoming more aware of the enormous risks of pollution. However, information on the relationship between exposures of population to pollution, particularly PM2.5 urban concentrations, is not completely clear for the public and even for environmental authorities. Although, WHO has published guidelines for this, their interpretation to actual urban situations in underdeveloped countries cities is somewhat confusing. The author has review, WHO guidelines and applied them to the particular situation in the city of Medellín and the Aburrá Valley region, in Colombia. This region, because of its topography and climate, experiments high PM2.5 episodes in some months of the year, and when that occurs, there are all kind of speculation in the media about this and about the high numbers of death people that this causes. It is proposed to have a more equilibrated approach on this issue when taking mitigating measures and when communicating to the people on the health effects associated. At the same time, it is important to promote research on health issues and their relationship with the environment at the local level, and also to understand the local factors that relate climate, atmospheric visibility and pollution episodes. There must be efforts to establish sensible mitigation and protection of people and property in the face of pollution episodes and not just stimulate fear and a chain of accusations and finger pointing among the communities based on misguided interpretations of the health effects of pollution episodes.

Groundnut husk (GH) and Rice husk (RH) were used as adsorbents to remove Mn2+, Zn2+ and Pb2+ ions from fertilizer industrial waste water. Continuous adsorption experiment was conducted to examine the effect of adsorbent mass, pH, temperature and adsorbent combination on adsorption of Mn2+, Zn2+ and Pb2+ from fertilizer industrial waste water. The results showed that the adsorption of the metal ions was adsorbent mass, pH, and temperature dependent. The optimum adsorbent mass was 60 g, optimum pH was pH 5 and pH 6 and optimum temperature was 60°C for adsorption of heavy metal ions. The Langmuir biosorption isotherm provided the best fit for sorption of Mn2+, Zn2+ and Pb2+ using groundnut husk as indicated by their correlation coefficient (R2) of 0.998, 0.676 and 0.297 while the freundlich biosorption isotherm had the best fit using rice husk as indicated by their correlation coefficient (R2) of 0.332, 0.041 and 0.556 for Mn(II), Zn(II) and Pb (II) respectively. The study also showed that groundnut husk and rice husk can be efficiently used as low cost alternative for removal of Mn2+, Zn2+ and Pb2+.

Background: The megacity status of Lagos has led to increased pressure on the urban environment especially on air quality. Twelfth decade of serving as Nigeria former capital and currently the economic nerve centre of the country, there is yet no holistic information on source apportionment of atmospheric aerosols in the city. Hence, the study was conducted to provide an understanding of the chemical compositions and source identifications of PM2.5 (aerodynamic diameter, dae ≤ 2.5 μm) and PM2.5-10 (2.5 μmae<10 μm) particulate matter over Lagos, Nigeria.

Methods: Sampling of PM2.5 (fine) and PM2.5-10 (coarse) were collected on nuclepore polycarbonate filters using a low volume GENT sampler (Schlumberger Model: M250) equipped with double staged stacked filter units. A total of 192 samples were collected (96 of each fraction). Elemental analyses of both fractions were carried out using Particle Induced X-ray Emission (PIXE) while Proton Induced Gamma-ray Emission (PIGE) was also employed to complement for X-ray self-absorption effect among low Z elements by PIXE technique.

Results: Data on twenty-four elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, Zr, Cs and Pb) detected in both particulate sizes were displayed, discussed. Receptor modelling of the data for source apportionment and identification were achieved for both fractions via positive matrix factorization (PMF). Five source categories with stable profiles were identified in both fractions.

Conclusions: The study concluded that anthropogenic emissions from gasoline oil combustions, industrial, and biomass burning emissions were more predominant and could pose great hazard to Lagos receptors during the sampling period.

Bismuth (Bi) is a ubiquitous metal, but its effects on human health are unknown. We examined the cytotoxicity of Bi compounds to cultured 8505C human thyroid cancer cells. Treatments of 0.05–0.1 mM of Bi subgallate and free gallic acid resulted in cell death in approximately 100% of cells.

Multiple heavy metals are known to cause renal insufficiency and necrosis, details on the toxic mechanism are still lacking. We investigated the cytotoxicity of 12 heavy metals to the 8505C thyroid cancer cells at concentrations of 10−3–105 μM. Notable decreases in cell viability were observed in exposures to four metals in the divalent cation form (nickel, copper, zinc and cadmium) at concentrations ≥ 1 μM. The effect of cadmium on cell death was substantial. In addition, the toxicity of 3 μM cadmium to the cells was inhibited by the addition of high concentrations (300 μM) of calcium or selenium, but intracellular levels of cadmium increased.

Children are frequently exposed to significant hazard for organophosphate poisoning (OP) in their environment; since the brain is growing during this period and it is extra liable to neurotoxicants. The aim of this work was to determine the relationship between urinary concentrations of dialkylphosphates (DAP) metabolites, which are biomarkers of OP pesticide exposure, and attention-deficit/hyperactivity disorder (ADHD) in Egyptian children aged seven to twelve years. A case-control study was conducted at Alzhraa University hospital. We recruited 40 children diagnosed as ADHD according to “the diagnostic and statistical manual of mental disorder (DSM-5) criteria” by psychiatrist. Control group of 40 healthy children who did not have any psychiatric or neurologic disorders, age and sex matched. Exposure was determined by analyzing six urinary metabolites of DAP. We investigated the association between ADHD subtypes, coincidence of epilepsy and OP exposure. Significant increase in urinary level of all DAP metabolites for children with ADHD in comparison to control group except Diethyl-dithio-phosphate. ADHD children with epilepsy had statistically significant elevated level of urinary Dimethyl-dithio-phosphate, Diethyl- phosphate and Dimethyl-phosphate metabolites in comparison to those without epilepsy. By logistic regression analysis, Children with high level of urinary Dimethyldithio- phosphate (OR=2.29), Diethyl-phosphate (OR=2.40), Dimethyl-phosphate (OR =2.02), and Dimethyl-thiophosphate (OR=1.82) have two fold increased risk of developing ADHD than those having lower concentration of these metabolites. Our findings back up the theory that existing environmental concentration of organophosphate pesticide exposure may lead to the development of ADHD and increase the risk of epilepsy in ADHD children.

The biggest landfill in Mexico comprehends an area of 375 hectares and 72 million tons of solid wastes were deposited during 20 years until his closure in December 2012. On the other hand, there is concern of the use of landfill biosolids as feedstock for wastewater treatment plants. Leachate and sludge samples were taken from this landfill and a wastewater treatment plant. Polybrominated Diphenyl Ethers (PBDEs), tetrabromobisphenol A (TBBP-A) and hexabromocyclodecanes (HBCDs) were determined in all samples. This study provides valuable information about BFRs contents and possible release into environment. Results obtained for total PBDEs ranged from not detected (n. d.) to 3.88 ± 0.38 ng mL-1 in leachates and from n. d. to 23.4 ± 4.7 ng g-1 in sludges. HBCD was quantified in the range of 0.161 ± 0.014 to 0.666 ± 0.453 ng mL-1 in leachate and from 0.112 ± 0.042 to 34.873 ± 8.262 ng g-1 in sludge samples. TBBP-A, β-HBCD and BDE-209 were not found in any sample. According to characteristics of the landfill and samples properties, BFRs could proceed from wastes and re-injection of leachates into garbage. Our results suggest the improvement of waste treatment or implementation of remediation procedures.

The basin of the Rio Mogi Guaçu has one of the best fish faunas studied in Brazil. Their fish are an important source of food for the inhabitants of the region, but due to human impact suffering along its course, it is relevant to do an analysis of contamination by trace elements. The objectives of this study were to analyze the presence of trace elements, copper, chromium, lead and zinc, and compare the trace element concentration in muscles and fish liver and intestinal parasites. 229 specimens were collected in 2012 of Prochilodus lineatus, known as curimbatá, in Cachoeira de Emas, Pirassununga. Muscle and liver samples were collected and analyzed to obtain the concentration of trace elements as well as intestinal parasites to evaluate the investigated analytes. Atomic absorption spectrometry in flame mode (F AAS) and graphite furnace mode (GF AAS) was employed to quantify the analytes. Digestion samples were analyzed using method EPA-3050B (modified). The concentration of trace elements in parasites Neoechinorhynchus curemai was higher than in the fish tissues indicating that these organisms can be good indicators of the presence of trace elements and pollution.

HPLC-HRMS method for detection of Furanoylfentanyl and its metabolites in the urine is developed. For this it is proposed the implementation of an approach using targeted searches for finding the most probable metabolites, basing on their calculated exact mass and fragmentation regularities. HRMS spectrum of Furanoylfentanyl and its metabolites are obtained.

According to the analyses of grain size and major element distribution in the Aqiang loess section AQS3 in the north piedmont of the Kunlun Mountains in China, the peaks and valleys in the loess and loess-like sandy sedimentary facies displayed clear variations in their mean particle diameter, standard deviation, SiO2, Al2O3, TOFE (Fe2O3+FeO), and (Al2O3+TOFE)/SiO2 ratio. Both grain size and major element distributions showed 19 cycles of alternation among the sedimentary facies. Results suggested that the observed cycles mainly resulted from fluctuations between the coldarid and warm-humid climates. Most warm periods in the AQS3 corresponded well to the D/O events recorded by the ice-core oxygen isotope in the GRIP during the MIS3. This study suggests that high-frequency climatic fluctuations on millennial scale occur in the north piedmont of the Kunlun Mountains, and they are regional responses to global climate changes during the MIS3.

Coimbatore city also known as Manchester of Tamil Nadu, is an industrial city. The study area is facing the problem of groundwater depletion and the quality is deteriorated to a greater extent. In this study, the quality of groundwater for its suitability for drinking and irrigational purposes was assessed by its hydro chemical parameters. Seventy eight groundwater samples were collected within the study area during post monsoon season of the year 2011.The samples were tested for the physical and chemical parameters. Geographic Information System (GIS) based analysis has been carried out to find out the quality of groundwater for drinking and irrigational purposes. Potassium concentration is found to exceed the maximum allowable limits in 62.82% of samples. Sulphate (SO4) concentration of all the samples was found to be within allowable limits. Based on the study, it was found that most of the samples are suitable for irrigation purpose.

Automobile emission and anthropogenic activities has been found to constitute a major sources of air pollution. This work investigated the level of some heavy metals (Pb, Cd, Fe and Zn) in street dust of Bachure, Chemistry Department, Jaga-Jaga Market, Vonuklang and Shinko, Adamawa state, Nigeria. The results showed that the highest and lowest metal concentrations were found in the heavy traffic sites, anthropogenic activities and control sites respectively. The concentration of Pb was observed to increase from 1.24 μg/m3 in Bachure to 2.89 μg/m3 in Shinko. Cd was also observed to increase from 0.016 μg/m3 in Bachure to 0.066 μg/m3. Fe was observed to be between 18.60 in Bachure to as high as 34.80 μg/m3 in Shinko, while Zn was observed to be between 2.4 in Bachure to as high as 5.4 μg/m3 in Shinko. The concentration of all the heavy metals were observed to be higher than the permissible health limit for urban areas recommended by environmental protection agency (EPA).

MIC disaster has been established as one of the largest industrial disasters which claimed>10000 lives and seriously jeopardized lives of millions. Besides acute illness and multi-system complications, genetic damage at chromosomal level was indicative of long-term illness as demonstrated in individual reports. Presence of self-replicating minutes detected after 1114 days indicated persistence of rearrangements in the exposed individuals. Among the systemic complications, respiratory, ophthalmic and reproductive systems were significantly affected then and now. Some of the females with elevated chromosome abnormalities had history of fetal loss and high incidence of perinatal and neonatal mortality. Several in vivo and in vitro experiments concluded that MIC may exert geno-toxicity by binding of carbamoylating agents to nuclear proteins. The cancer-incidence among the MIC-exposed survivors is calculated from hospital records. Moreover, continuous soil contamination by multiple of chemical wastes in the site might have augmented the genetic changes through interaction with other biologic and a-biologic factors. Owing to variable latency period of chemicals, and also unavailability of genetic information measured in stratified cohorts immediately after the disaster, it is worthy of screening genetic condition in the exposed survivors and their progenies, though 32 years have gone. This review further pays importance to compounding effects of multiple confounding variables on the exposed individuals. Nevertheless, comparison of a current genetic screening with the previous genetic condition would actually discuss about the long-term genotoxic effect of MIC on Bhopal population; however, such exercise would not be a straightforward approach due to interaction of several confounders.

The transition metal oxide Cd-Ce-TiO2 catalysts were prepared by the method of coprecipitation. The catalysts were characterized by means of XRD, BET, SEM, TEM, Raman and UV-Vis DRS. And the catalytic activities of the catalysts for deNOx were evaluated by NH3-SCR reaction. The nanoparticles will be formed for Cd-Ce0.2-TiOx catalysts with the different metal Cd contents. The catalysts possess the irregular, mesoporous structure. XRD and Raman data demonstrated that at the low content of Cd, anatase structure disappeared in the catalyst, but the amorphous oxide was formed. And BET pore size distribution shows the formation of the mesoporous structure in the mixed-oxide. Among all the catalysts, 2% Cd-Ce0.2-TiOx catalyst exhibits the best NH3-SCR performance with a wide temperature window from 225 to 525°C for NO conversion above 90%.

The ability of the macro-fungus, Pleurotus ostreatus and non-ionic surfactant (Triton X-100) to degrade crude oil in crude oil polluted soil was investigated with a view to ascertain their efficacy in reducing the toxicity of polluted ecosystem. Crude oil polluted soil samples (2000 g) contained in polypropylene bags (20 cm diameter x 20 cm height) were inoculated with P. ostreatus mycelium and triton x-100 and incubated at 28 to 30°C for 60 days. Crude oil polluted soil samples were analyzed before inoculation and incubation and they served as the control. In all the heavy metals quantified (Pb, Cu, Mn, Cd and Ni), there is a significant difference at P ≤ 0.05 when all the amended cells (B to D) are compared with the control cell (A). For Pb, the concentration of all the cells amended significantly reduced with cells C (PSS+Triton x-100) having the lowest concentration of 1.52 ± 0.02 when compared with the control cell (11.31 ± 0.15). For Cu, Cd and Ni, all the amended cells were seen to be reduced in their concentrations when compared with the concentration of the control sample. For Mn, the concentrations of the amended cells were seen to be high when compared with the concentration of the control sample. For all the mineral elements analyzed (Ca, Mg, Na and K), there is a significant difference at P ≤ 0.05 when all the amended cells (B to D) are compared with the control cell (A). For Ca, there was a significant difference (P ≤ 0.05) when cell A is compared with other cells. Highest reduction in Ca level was seen in cell D (PSS+Pleurotus ostreatus+Triton X-100) with the value of 88.28 ± 2.72. For Mg, all the amended cells were seen to have a significant increase in their values when compared with the control sample (271.15 ± 0.45). For Na and K, only cell B had the highest value of 90.18 ± 0.73 for Na and 371.54 ± 2.26 for K. Cell C was observed to be slightly reduced for Na while cell C and D were also seen to be reduced for K. These results showed that white rot fungus (P. ostreatus) and triton x-100 were able to degrade the polluting oil and as such may be suitable for remediating crude oil polluted soil.

The main purpose of this work was to assess the removal of the herbicide oxyfluorfen and chemical oxygen demand (COD) in aqueous solution using the electrocoagulation process. The results showed that the maximum removal efficiency for oxyfluorfen and COD were (98.5% and 90%), (99.2% and 85%) and (96.1% and 70.5%) at 30 min by using iron (Fe), stainless steel (S.S) and aluminum (Al) as anode respectively, at a current density of 75 mA.cm-2 and pH of 5.8. The energy consumption in the electrocoagulation process at optimum conditions (15.9, 16.65 and 14.1 KWh/m3) using Fe, SS and Al electrodes respectively. The adsorption of oxyfluorfen preferably fitting the Freundlich adsorption isotherm. The adsorption process follows the first order kinetic model with good correlation.

With the increasing demand for and reliance on plastics as an everyday item, and rapid increase in their production and subsequent indiscriminate disposal, the environmental implications of plastics are of growing concern. Given that plastic polymers are highly resistant to degradation, the influx of these persistent, complex materials is a risk to human and environmental health. Microplastics is described as a truly heterogeneous mixture of particles ranging in size form a few microns to several millimetres in diameter; including particles of various shapes from completely spherical to elongated fibres. Microplastic pollution has been reported on a global scale from the poles to the equator. The main route of concern is currently as a consequence of ingestion, which could lead to physical and toxicological effects on aquatic organisms.

To this end, in order to minimize the negative impacts posed by plastic pollution (microplastics), a plethora of strategies have been developed at various levels to reduce and manage the plastic wastes. The main objective of this paper is to review some of the published literatures on management measures of plastic wastes.