42 research outputs found
Frequency of malaria and glucose-6-phosphate dehydrogenase deficiency in Tajikistan
BACKGROUND: During the Soviet era, malaria was close to eradication in Tajikistan. Since the early 1990s, the disease has been on the rise and has become endemic in large areas of southern and western Tajikistan. The standard national treatment for Plasmodium vivax is based on primaquine. This entails the risk of severe haemolysis for patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Seasonal and geographical distribution patterns as well as G6PD deficiency frequency were analysed with a view to improve understanding of the current malaria situation in Tajikistan. METHODS: Spatial and seasonal distribution was analysed, applying a risk model that included key environmental factors such as temperature and the availability of mosquito breeding sites. The frequency of G6PD deficiency was studied at the health service level, including a cross-sectional sample of 382 adult men. RESULTS: Analysis revealed high rates of malaria transmission in most districts of the southern province of Khatlon, as well as in some zones in the northern province of Sughd. Three categories of risk areas were identified: (i) zones at relatively high malaria risk with high current incidence rates, where malaria control and prevention measures should be taken at all stages of the transmission cycle; (ii) zones at relatively high malaria risk with low current incidence rates, where malaria prevention measures are recommended; and (iii) zones at intermediate or low malaria risk with low current incidence rates where no particular measures appear necessary. The average prevalence of G6PD deficiency was 2.1% with apparent differences between ethnic groups and geographical regions. CONCLUSION: The study clearly indicates that malaria is a serious health issue in specific regions of Tajikistan. Transmission is mainly determined by temperature. Consequently, locations at lower altitude are more malaria-prone. G6PD deficiency frequency is too moderate to require fundamental changes in standard national treatment of cases of P. vivax
Metabolic profiling detects early effects of environmental and lifestyle exposure to cadmium in a human population
Background: The ‘exposome’ represents the accumulation of all environmental exposures across a lifetime. Topdown
strategies are required to assess something this comprehensive, and could transform our understanding of
how environmental factors affect human health. Metabolic profiling (metabonomics/metabolomics) defines an
individual’s metabolic phenotype, which is influenced by genotype, diet, lifestyle, health and xenobiotic exposure,
and could also reveal intermediate biomarkers for disease risk that reflect adaptive response to exposure. We
investigated changes in metabolism in volunteers living near a point source of environmental pollution: a closed
zinc smelter with associated elevated levels of environmental cadmium. Methods: High-resolution 1H NMR spectroscopy (metabonomics) was used to acquire urinary metabolic profiles
from 178 human volunteers. The spectral data were subjected to multivariate and univariate analysis to identify
metabolites that were correlated with lifestyle or biological factors. Urinary levels of 8-oxo-deoxyguanosine were
also measured, using mass spectrometry, as a marker of systemic oxidative stress. Results: Six urinary metabolites, either associated with mitochondrial metabolism (citrate, 3-hydroxyisovalerate, 4-
deoxy-erythronic acid) or one-carbon metabolism (dimethylglycine, creatinine, creatine), were associated with
cadmium exposure. In particular, citrate levels retained a significant correlation to urinary cadmium and smoking
status after controlling for age and sex. Oxidative stress (as determined by urinary 8-oxo-deoxyguanosine levels)
was elevated in individuals with high cadmium exposure, supporting the hypothesis that heavy metal
accumulation was causing mitochondrial dysfunction. Conclusions: This study shows evidence that an NMR-based metabolic profiling study in an uncontrolled human
population is capable of identifying intermediate biomarkers of response to toxicants at true environmental
concentrations, paving the way for exposome research.
Keywords: metabonomics, cadmium, environmental health, exposome, metabolomics, molecular epidemiolog
Co-composting: An Opportunity to Produce Compost with Designated Tailor-Made Properties
AbstractCo-composting is a technique that allows the aerobic degradation of organic waste mixtures, primarily aiming at obtaining compost that can be used as fertiliser or soil amendment. As compared to the typical composting activity, the main difference is not merely the use of more than one feedstock to start and sustain the biodegradation process, but also the possibility of combining various kinds of waste to obtain 'tailored' products with designed properties, or to reclaim and valorise natural resources, such as degraded soils or polluted soils and sediments. Set up of appropriate co-composting protocols can be a way to optimise the management of waste produced by different sectors of agriculture and industry and also from human settlements. Different formulations can not only optimise the biodegradation process through the adjustment of nutrient ratios, but also lead to the formation of products with innovative properties. Moreover, co-composting can be a technique of choice for the reclamation of soils degraded by intensive agriculture or contaminated soils and sediments. In fact, an appropriate mix of organic waste and soils can restore the soil structure and induce fertility in nutrient-depleted soils, and also remediate polluted soils and sediments through degradation of organic pollutants and stabilisation of heavy metals. While the selection of different mixes of organic waste may lead to the design of composts with specific properties and the potential valorisation of selected waste materials, there are still several factors that hamper the development of co-composting platforms, mainly insufficient knowledge of some chemical and microbiological processes, but also some legislative aspects. This chapter illustrates the progress achieved in co-composting technology worldwide, some key legislative aspects related to the co-composting process, the main scientific and technical aspects that deserve research attention to further develop co-composting technology, and successful applications of co-composting for the reclamation of soils and sediments, allowing their use for cultivation or as growing media in plant nurseries. A specific case study of the production of fertile plant-growing media from sediment co-composting with green waste is also illustrated
Barley yield and soil microbial and enzyme activities as affected by contamination of two soils with lead, zinc or copper
The effects of increasing rates of Pb, Zn and Cu on extractable heavy metal levels, barley yields, basal respiration and the activities of catalase, urease, invertase and acid phosphatase were investigated in two soils in a 2-year greenhouse experiment. In the first year, barley yields were decreased by increasing additions of Pb, Zn and Cu. In the second year, increased yields were recorded at lower rates of addition of all three metals in both the chestnut and chernozem soils. Yield depressions were most marked for added Cu and least marked for Pb but, in contrast, accumulation of heavy metals in grain, in excess of recommended limits, was most pronounced for Pb and did not occur for Cu. Increasing rates of all three metals caused a decrease in basal respiration; the degree of inhibition was generally greater in the second than in the first year. After 1 year of incubation, increasing rates of addition of metals reduced all tested enzyme activities. However, after 2 years, the pattern of response was more complex, with increases in enzyme activities being noted at lower rates of addition of all three metals. In general, invertase and urease activities were more markedly inhibited by heavy metal contamination than those of catalase and phosphatase. Ammonium acetate-extractable heavy metal concentrations in soils were less after 2 years than 1 years reaction time due to their transformation into less labile forms. Significant negative correlations between grain yield, basal respiration and enzyme activities were observed in both years
Modeling of Respiratory System Dysfunction Among Nuclear Workers: A Preliminary Study
Numerous studies have reported on cancers among Mayak Production Association (PA) nuclear workers. Other studies have reported on serious deterministic effects of large radiation doses for the same population. This study relates to deterministic effects (respiratory system dysfunction) in Mayak workers after relatively small chronic radiation doses (alpha plus gamma). Because cigarette smoke is a confounding factor, we also account for smoking effects. Here we present a new empirical mathematical model that was introduced for simultaneous assessment of radiation and cigarette-smoking-related damage to the respiratory system. The model incorporates absolute thresholds for smoking- and radiation-induced respiratory system dysfunction. As the alpha radiation dose to the lung increased from 0 to 4.36 Gy, respiratory function indices studied decreased, although remaining in the normal range. The data were consistent with the view that alpha radiation doses to the lung above a relatively small threshold (0.15 to 0.39 Gy) cause some respiratory system dysfunction. Respiratory function indices were not found to be influenced by total-body gamma radiation doses in the range 0–3.8 Gy when delivered at low rates over years. However, significant decreases in airway conductance were found to be associated with cigarette smoking. Whether the indicated cigarette smoking and alpha radiation associated dysfunction is debilitating is unclear
Use of inorganic wastes as immobilizing agents for soluble P in green waste-based composts
The study examines the effectiveness of red mud, blast furnace (BF) slag, and alum-derived water treatment sludge as immobilizing agents for excessive soluble P that had accumulated in three green waste-based composts.The three wastes were applied at 0%, 5%, 10%, and 20% w/w to three different composts, all containing extremely high concentrations of extractable P, and were incubated for 60 days. Water-soluble P was measured regularly throughout the incubation period, and at the end, P extractable with resin, 0.05 M NaHCO(3), and 0.005 M H(2)SO(4) were also measured.In the water extracts, inorganic P made up more than 85% of the total P present. All three materials had the ability to adsorb P and thus lowered water-soluble P concentrations. Water treatment sludge was clearly the most effective material, and this was attributed to its amorphous nature (thus, large Brunauer-Emmett-Teller surface area) and its acid pH (6.8) compared with the alkaline pH (10-11) of the other two materials. Water treatment sludge was also the most effective at lowering resin- and NaHCO(3)-extractable P. When H(2)SO(4) was used as the extractant, BF slag tended to be the most effective material at lowering extractable P, followed by water treatment sludge, and red mud. That is, the P immobilized by water treatment sludge was extractable with acid but not with water, resin, or NaHCO(3).Water treatment sludge has the potential to be used as an effective immobilizing agent for soluble P in composts, and it should be trialed under field conditions