Considerable Environmental Pollution Research Articles

Associations between plasma metabolites and heavy metal exposure in residents of environmentally polluted areas

Heavy metals are commonly released into the environment through industrial processes such as mining and refining. The rapid industrialization that occurred in South Korea during the 1960s and 1970s contributed significantly to the economy of the country; however, the associated mining and refining led to considerable environmental pollution, and although mining is now in decline in South Korea, the detrimental effects on residents inhabiting the surrounding areas remain. The bioaccumulation of toxic heavy metals leads to metabolic alterations in human homeostasis, with disruptions in this balance leading to various health issues. This study used metabolomics to explore metabolomic alterations in the plasma samples of residents living in mining and refining areas. The results showed significant increases in metabolites involved in glycolysis and the surrounding metabolic pathways, such as glucose-6-phosphate, phosphoenolpyruvate, lactate, and inosine monophosphate, in those inhabiting polluted areas. An investigation of the associations between metabolites and blood clinical parameters through meet-in-the-middle analysis indicated that female residents were more affected by heavy metal exposure, resulting in more metabolomic alterations. For women, inhabiting the abandoned mine area, metabolites in the glycolysis and pentose phosphate pathways, such as ribose-5-phosphate and 3-phosphoglycerate, have shown a negative correlation with albumin and calcium. Finally, Mendelian randomization(MR) was used to determine the causal effects of these heavy metal exposure-related metabolites on heavy metal exposure-related clinical parameters. Metabolite biomarkers could provide insights into altered metabolic pathways related to exposure to toxic heavy metals and improve our understanding of the molecular mechanisms underlying the health effects of toxic heavy metal exposure.

Magnetic separation for recovering iron resources from acid-leaching tailings of laterite nickel ore through mineral phase transformation

The acid-leaching tailings of laterite nickel ore is a typical hazardous waste in the laterite nickel ore industry. The current treatment involves stacking and landfills, which leads to considerable environmental pollution and resource wastage. The reduction of hazardous waste and the recovery of iron resources have environmental and economic value. In this study, a mineral phase transformation technology was proposed. The suitable transformation conditions were 700 ℃, 30 min, and 30 % CO, and optimal grinding and magnetic conditions were −37 μm content 92.42 % and 143.35 kA·m−1, respectively. Then the iron grade and recovery reached 52.00 % and 80.11 %, respectively. Meanwhile, hematite has converted into strongly magnetic magnetite with saturation magnetization increased from nearly 0 A·m2·kg−1 to 28.49 A·m2·kg−1. And particles transformed from dense to a porous honeycomb structure. Therefore, the mineral phase transformation achieves recovering iron resources during reducing hazardous waste. It proposed a new way of resource utilization of laterite nickel ore acid-leaching tailings which has positive environmental and resource benefits.

Selective Quantification of Organic and Inorganic Arsenic in Kelp Thalli and Kelp-Based Products

Kelp can accumulate large quantities of arsenic compounds even in the absence of considerable environmental pollution. A substantial difference in toxicity between organic and inorganic arsenic compounds makes the form of arsenic relevant for the risk assessment of consuming kelp thalli and kelp-based products.The aim of the study was to develop an analytical procedure for the selective quantification of organic and inorganic arsenic in kelp thalli by inductively coupled plasma mass spectrometry and solid-phase extraction without scheduled precursors.Materials and methods. The authors studied samples of Laminaria saccharina and Laminaria japonica, spiking mixtures of chemical compounds containing arsenic in different oxidation states, and bioactive dietary supplements based on kelp thalli. Solid-phase extraction was performed using Maxi-Clean SAX cartridges. The arsenic content was determined using an Agilent 7900 inductively coupled plasma mass spectrometer.Results. Microwave-assisted extraction with deionised water ensures 91% recovery of arsenic-containing compounds from kelp thalli, and the addition of hydrogen peroxide to the extractant provides complete extraction. Solid-phase extraction with an eluent based on 3% H2O2 can extract the organic fraction from a mixture of organic and inorganic arsenic compounds without washing the inorganic fraction off the cartridge.Conclusions. The authors offer an effective analytical procedure for the selective quantification of organic and inorganic arsenic in kelp thalli and kelp-based products. This procedure allows for the isolation of arsenic-containing compounds from the organic matrix of kelp with 3% hydrogen peroxide. Solid-phase extraction with this extractant can effectively separate organic and inorganic fractions without prior neutralisation of the test solution.

Promoting the utilization efficiency of agrochemicals via short-chain nonionic fluorinated synergist: Strategies and working mechanisms

Wastage of agrochemicals results in considerable environmental pollution and economic loss. The use of trisiloxane surfactants as synergists has proven to allow for reduction in agrochemical application rates, but these surfactants show poor resistance to hydrolysis, which can attenuate their synergistic effects. Herein we report the development of a short-chain nonionic fluorinated surfactant, designated mPEG200-TEOH-6, as a novel agrochemical synergist. In contrast to conventional long-fluorocarbon chain surfactants, our short-chain fluorinated surfactant can avoid the risk of persistence and bioaccumulation in the environment. We determined the thermal storage stability of mPEG200-TEOH-6 and investigated its effects on the static surface tension, dynamic surface tension, contact angle, and thermal storage stability of four agrochemicals solutions, which explained its synergistic efficacy. In addition, we compared its effects with those of the commercial surfactant Silwet 408. Both mPEG200-TEOH-6 and Silwet 408 clearly improved the utilization efficiency of the agrochemicals, but mPEG200-TEOH-6 displayed substantially greater synergistic efficiency than Silwet 408; specifically, the former markedly decreased the static surface tension of agrochemical solutions, increased their diffusivity and wettability, and decreased their LC50 values. Strikingly, we found that mPEG200-TEOH-6 was more stable than Silwet 408 under thermal storage conditions. The result presented herein can be used to guide the use of surfactants and agrochemicals in agriculture.

Additive manufacturing of an Fe–Cr–Co permanent magnet alloy with a novel approach of in-situ alloying

Additive manufacturing has become increasingly important in the production of magnetic materials in recent years due to the great demands for miniaturization and complex-shaped magnet parts. In this study, the laser beam-powder bed fusion process (LPBF) has been used to develop an in-situ alloying process for the additive manufacturing of a permanent magnet material of the Fe–Cr–Co system. This novel method allows for the production of complex alloys with a chemical composition suited to each specific case of application, achieved by using elemental powders or simpler commercial alloy powders as base materials. The core focus of this study has been on the development and characterization of the printing process using a Fe-30.5Cr-15Co-1.5Mo alloy. The in-situ alloying process has been developed by performing melt pool tests on the two main component powders Fe and Cr and by conducting parameter studies using two different powder mixtures with different sphericity of their components. The influence of different printing parameters and post-printing treatments on the chemical homogeneity and magnetic properties has been studied for selected samples. In addition, magnetic measurements at different temperatures have been performed to investigate the temperature stability of the magnetic properties of the 3D printed material.Impact StatementAs by today, the current amount of research done on the additive manufacturing of magnetic materials is rather low. Most of research is focused on rare- earth containing magnetic materials. In this work therefore, we are taking another direction in which we will show that LPBF combined with in- situ alloying is an ideal method for the production of a great variety of different rare- earth free magnetic materials. The positive results of our work can both have an influence on the the scientific community, as further research in the field on different promising rare- earth free magnetic materials is to be expected. Furthermore, a positiv economic impact may occur since the production of rare- earth free magnetic materials is dependent on different raw material sources which are both more cost- effectiv and less critical in terms of their supply chain. This effect is also accompanied by a positive environmental impact, since the mining of rare- earth metals usually comes with considerable environmental pollution.

Research on an Efficient Deep-Hole Application Method for Liquid Fertilizer Based on Alternate Drilling

Liquid fertilizers are mainly applied by spraying liquid fertilizer on the surface of crop leaves and by deep openings between rows. The first causes considerable environmental pollution, and the second can easily cause to damage the root system of crops. In this study, corn crops were taken as the study object and an efficient deep-hole application method for liquid fertilizer based on alternate drilling was proposed. The needle body is driven by the spur gear wheel system in a caving mechanism to puncture holes alternately in a vertical posture and high-speed punctures are implemented with less disturbance to the soil. The cylindrical hollow cam of the mechanism is controlled so that the fertilizer needle sprays fertilizer when injected into soil and stops injecting when pulled out of the soil. Based on the bench test, fertilizer injecting performance and energy saving performance of the differential two-way fertilizer supply distribution device were analyzed and the head loss for energy saving value is 2.1, 3.1, and 5.5 m. Based on numerous field tests, the puncture track, hole width, and hole spacing are analyzed under different puncture speeds. Field tests were carried out according to a quadratic orthogonal rotating combination design and the results show that when the fertilization depth for agronomic requirements is 80 mm and the machine work speed and forward speed are 127 r min−1 and 1.40 m s−1, respectively, the hole width is 39.9 mm, the hole spacing is 320 mm. The efficient deep-hole application method for liquid fertilizer based on alternate drilling can provide support for data analysis and theoretical design of liquid fertilizer deep application technology for corn crops.

One-pot superhydrophilic surface modification of waste polyurethane foams for high-efficiency oil/water separation

Despite of the fact that polymers have brought tremendous convenience to human life, they have also inevitably caused considerable environmental pollution after their service life. Therefore, a feasible strategy that can effectively recycle waste polymers and endow them with high added value is much desired. Superwetting materials have shown great promise in oily wastewater treatment because of their high oil/water separation efficiency. However, most of these materials present some limitations, such as complex preparation procedures and poor salt tolerance, which hamper their practical applications. In this study, an iron hydroxide@polydopamine@waste polyurethane foam (Fe(OH)3@PDA@WPU) was synthesized via a facile and mild “one-pot” reaction. During this process, polymerization of dopamine and in situ growth of Fe(OH)3 were simultaneously realized, and the resultant PDA and Fe(OH)3 nanoparticles were firmly attached to the surface of WPU. Due to the abundant hydrophilic groups from PDA and Fe(OH)3 coupled with the surface roughness created by Fe(OH)3 nanoparticles, the surface properties of the foam could be changed from hydrophobic to superhydrophilic. Remarkably, the Fe(OH)3@PDA@WPU was capable of separating various oil/water mixtures even under some severe conditions (e.g. erosion in a saturated sodium chloride solution and longtime sonication), demonstrating high potential in marine oily sewage treatment. Moreover, this work also paved a new path for reducing the negative impact of waste polymer foams on our environment, and in the meantime realizing their high value utilization.

Recovery of antioxidant from Decapterus Macarellus waste using wet rendering method

In Malaysia, Decapterus Maruadsi is widely used as the main ingredient in food products such as ‘keropok lekor’ and fish cracker. The wastes generated from the fish snack industry are underutilized and most are discarded into the sea, generating considerable environmental pollution. The recovery of antioxidants in the fish wastes could lead to the development of a very exciting and promising alternative source of commercial antioxidant compounds. The objective of the present work is to investigate the effect of temperature, type of solvent, extraction time, and ratio of sample to solvent loading in the extraction of antioxidants from Decapterus Maruadsi waste using the wet rendering method. The collected fish waste of Decapterus Maruadsi was pre-treated and then subjected to a wet rendering treatment at 0–60 °C for 30–150 min with ratio of sample to solvent loading of between 1:10 and 9:10 (w/v). The presence of antioxidant in the extract was analyzed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Total Phenolic Compound (TPC) assays. Based on the results of this study, wet rendering treatment performed for 90 min at 30 °C with a ratio of sample to solvent loading of 3:10 produced an extract with the highest concentration of active antioxidant compounds. Besides, only N-Acetyl-glutamic acid was identified with LCMS QTOF analysis. These results suggest that the fish waste of Decapterus Maruadsi can be exploited to become a source of antioxidants for food and pharmaceutical applications.

Application of carbon dots in analysis and detection of antibiotics

抗生素的过度使用对环境造成了极大破坏,对其进行监测控制刻不容缓。常用的分析检测技术,如高效液相色谱(HPLC)、气相色谱(GC)、高效液相色谱-串联质谱(HPLC-MS/MS)等具有高效快速、重现性好、可自动化操作等优点。但对环境样品中抗生素的检测存在样品前处理过程繁琐、检测灵敏度低、实验成本高等问题。结合现有的检测技术发展新型材料,对提高抗生素的检测灵敏度具有重要意义。碳点(CDs)是一种尺寸介于0~10 nm之间的新型纳米材料,具有小尺寸效应、优异的电学和光学性质、良好的生物相容性等优点,已被广泛应用于环境样品中抗生素的检测。该综述对近5年CDs与传感器、色谱分析技术结合检测抗生素的应用进行了总结,并对其发展前景进行了展望。该文总结了CDs与分子印迹传感器、适配体传感器、电化学发光传感器、荧光传感器及电化学传感器相结合,及其在抗生素检测中的应用;对涉及的比率型传感器、阵列传感器等先进分析方法进行了举例评述;对CDs作为色谱固定相分离抗生素进行了阐述。文献表明,CDs结合传感器检测抗生素可有效提高检测灵敏度,但对复杂环境样品中抗生素的检测还面临着构建高选择性传感器、开发新型材料及数据处理等方面的挑战;目前,CDs作为色谱固定相对抗生素的材料分离,仍处于初步研究阶段,分离机理尚不明确,有待进一步深入研究。总之,CDs在环境样品中抗生素的检测方面仍面临一系列问题,随着人们对CDs的深入研究以及各种分析检测技术的不断发展,CDs将会在抗生素等环境污染物的检测中发挥重要作用。

Mathematical Formulation for Prediction of Structural Performance of Green Geopolymer Concrete Beams and Columns

In order to minimise the environmental impact of the waste and its disposal processes and to reduce global warming by cement production, this study has focused on the demand. This research looked at how waste wood ash can be used to make geopolymer concrete beams and columns, which can be used to replace traditional reinforced concrete elements in the construction industry. Waste wood ash, a waste produced in the nearby hotel and manufacturing factories by burning the waste wood collected in the woodworking industry and throwing the ash to land causing considerable environmental pollution. Geopolymer is an innovative inorganically friendly, alkaline-based binding agent that stimulates the source material of aluminosilicate (such as metakaolin, fly ash and GGBS). For three types of concretes (30 percent WWA – 70 percent Fly ash Geo-polymer concrete, Fly ash Geo-polymer concrete, and Reinforced Cement Concrete), the mathematical formula for the behaviour of beams in deflection, ductility factor, flexural strength, and columns in load carrying ability, stress strain behaviour, and load-deflection behaviours were investigated in this study. The results showed that the inclusion of waste wood ash into geopolymer concrete contributed to the 42 and 28 percent increase of the capacity for beam and column. Furthermore, by replacing waste wood ash, the compotation of structural elements was improved in their rigidity and ductility. The derived mathematical equations were most suitable for the prediction of forecast.

Recent Advances in Nanotechnology-Based Biosensors Development for Detection of Arsenic, Lead, Mercury, and Cadmium.

Heavy metals cause considerable environmental pollution due to their extent and non-degradability in the environment. Analysis and trace levels of arsenic, lead, mercury, and cadmium as the most toxic heavy metals show that they can cause various hazards in humans’ health. To achieve rapid, high-sensitivity methods for analyzing ultra-trace amounts of heavy metals in different environmental and biological samples, novel biosensors have been designed with the participation of strategies applied in nanotechnology. This review attempted to investigate the novel, sensitive, efficient, cost-benefit, point of care, and user-friendly biosensors designed to detect these heavy metals based on functional mechanisms. The study’s search strategies included examining the primary databases from 2015 onwards and various keywords focusing on heavy metal biosensors’ performance and toxicity mechanisms. The use of aptamers and whole cells as two important bio-functional nanomaterials is remarkable in heavy metal diagnostic biosensors’ bioreceptor design. The application of hybridized nanomaterials containing a specific physicochemical function in the presence of a suitable transducer can improve the sensing performance to achieve an integrated detection system. Our study showed that in addition to both labeled and label-free detection strategies, a wide range of nanoparticles and nanocomposites were used to modify the biosensor surface platform in the detection of heavy metals. The detection limit and linear dynamic range as an essential characteristic of superior biosensors for the primary toxic metals are studied. Furthermore, the perspectives and challenges facing the design of heavy metal biosensors are outlined. The development of novel biosensors and the application of nanotechnology, especially in real samples, face challenges such as the capability to simultaneously detect multiple heavy metals, the interference process in complex matrices, the efficiency and stability of nanomaterials implemented in various laboratory conditions.

Toward a Global Green Smart Microgrid: An Industrial Park in China

Today, the global energy crisis is becoming more serious, which is manifested by the shortage of fossil fuels and considerable environmental pollution. As a supplement to large-scale centralized power generation, distributed energy resources, such as wind and photovoltaic (PV) power, provide a new way to solve the energy crisis.

Waste-Free Processing of Pea Grain to Optimize the Use of Starch Byproducts

Grain processing is a source considerable environmental pollution. 60% to 90% of the raw materials used in this industry are recyclable. This paper proposes a deep grain processing technology that can produce a variety of products with high added value. The authors hereof have developed and substantiated a waste-free pea grain processing technology that uses pea varieties selected by Federal Legume and Cereal Research Center, Oryol, Russia. This technology can produce high quality starch and its byproducts while also extracting the recyclables contained in pea grains: the germ and the seed husks, both of which have high added value.

Effective Separation and Beneficiation of Iron and Chromium from Laterite Sulfuric Acid Leach Residue

The utilization of laterite sulfuric acid leach residue has always been a challenge in the metallurgical industry. The current treatment involves deep-sea landfills, which leads to considerable environmental pollution and resource wastage. In this work, an effective method is proposed to recover iron and chromium from sulfuric acid leach residue. The effects of roasting temperature, reducing agent dosage, and reaction duration on the recovery of iron and chromium were investigated. The optimum conditions were as follows: roasting temperature of 1200 °C, reducing agent dosage of 30%, and reaction duration of 60 min. Results show that the concentrate contains 87% Fe and that only 0.7% S can be obtained with an iron recovery of 82%, indicating suitability for ironmaking. Meanwhile, 85% of chromium can be beneficiated in tailings at a chromium content of 3.5%. The microstructure and composition of reduction products were analyzed by XRD, SEM, and EDS to understand the phase transformation and the aggregation of the reduction products. Hematite in the leach residue is first reduced to FeS and Fe3O4 at low temperature and then reduced to metallic iron with increased temperature. Sulfur is combined with alunite to form FeS at a low temperature, and the decomposition of chromite at high temperature leads to the formation of chromium oxide. In a high temperature and reducing atmosphere, Cr2O3 reacts with FeS to transform Fe and CrS. Through the reduction roasting–magnetic separation process, most of the iron is beneficiated in the concentrate, and nonmagnetic minerals such as FeS and CrS remain in the tailings. Consequently, the separation and beneficiation of iron and chromium occur. The process is economically feasible and environmentally friendly and thus has great potential for the industrial-scale recycling of laterite sulfuric acid leach residue.

Valorisation of carrot and pineapple pomaces for rock buns development

Fast growing food processing industries generate large quantities of by-products including pomaces which have less use and create considerable environmental pollution. These by-products can be directly or indirectly used in the development of new food products. In this study, rock buns formulated at 95:5:0; 90:5:5; 85:10:5 and 80:15:5% for wheat flour: carrot pomace: pineapple pomace and 100:0:0% for the control respectively were investigated for their nutrient composition and sensory quality. Nutrient composition of the carrot and pineapple pomaces respectively showed high crude fibre content of 12.84% and 15.05%. Beta carotene and vitamin C concentrations of 2.07 mg/100 g and 15.05 mg/100 g were recorded for the carrot and pineapple pomaces respectively. Functional properties of the wheat and composite flours were determined and showed that water absorption capacity, oil absorption capacity, solubility, swelling power decreased with increased incorporation of carrot and pineapple pomaces while bulk density and dispersibility increased. Sensory evaluation of the rock buns prepared from the flour blends showed that the substitution of wheat flour with 15% carrot and 5% pineapple pomaces was the most accepted by the sensory panellists. Nutrient composition of the most accepted rock buns showed improved content of ash, crude fibre and beta carotene. Carrot and pineapple pomaces are thus promising ingredients that can be used in composite formulation with wheat flour for rock buns development.

An institutional approach to manure recycling: Conduit brokerage in Sichuan Province, China

With increases in living standards and dietary changes, the livestock sector has grown rapidly worldwide, which has led to considerable environmental pollution through livestock manure. Particularly in East Asia, meat production has increased fast. While part of the problem can be resolved by further processing manure into commercial organic fertilizer, technological solutions do face their limits in dealing with high pollution loads at farms. There is hence urgent need for policy instruments that could help mitigate environmental pollution. However, not much is known about related policy initiatives. This paper introduces a cooperative in Sichuan Province, China, which connects livestock farms to crop farms that are willing to use livestock breeders’ manure on their land. As no frameworks exist which could aid the analysis of such a cooperative, we develop a framework based on the concept of “brokerage”. Our analysis shows that for the case of Qionglai, structural conditions are favourable to the cooperative closing the nutrient cycle by means of brokerage. However, as our analysis shows, constraints to the cooperative’s effectiveness foremost come from its daily operations. Within the given institutional structure, further qualitative improvements should be undertaken in terms of manure processing and manure management. The application of the framework to manure recycling shows that the framework and brokerage in general are useful analytical concepts for the circular economy. We conclude that the framework could also be applied to other fields of the circular economy, like food waste or bioenergy.

Advances in the Value Addition to Foods-recent Trends

Value addition to foods may be done by several ways. It could be done by the use of preservative, food ingredients capable of eliciting functionalities and by fortification using micronutrients. There are novel and emerging food processing technologies that are possible to preserve the ingredients in the food intact. The shelf life enhancement of the processed food can be done by adapting newer packaging technologies. Food processing industries in many of the countries across the world generates huge quantity of by-products that can be put into use by value addition. These by-products have less use and create considerable environmental pollution. The by-products of the fruits, vegetables, etc. may be used for value addition adapting commercially viable approaches. Fermented foods are value added foods that could be developed using novel starters. It is also important to note the regulatory aspects of foods whenever the foods are preserved b y value addition

Chemoselective Hydrodehalogenation of Organic Halides Utilizing Two-Dimensional Anionic Electrons of Inorganic Electride [Ca2N]+·e.

Halogenated organic compounds are important anthropogenic chemicals widely used in chemical industry, biology, and pharmacology; however, the persistence and inertness of organic halides cause human health problems and considerable environmental pollution. Thus, the elimination or replacement of halogen atoms with organic halides has been considered a central task in synthetic chemistry. In dehalogenation reactions, the consecutive single-electron transfer from reducing agents generates the radical and corresponding carbanion and thus removes the halogen atom as the leaving group. Herein, we report a new strategy for an efficient chemoselective hydrodehalogenation through the formation of stable carbanion intermediates, which are simply achieved by using highly mobile two-dimensional electrons of inorganic electride [Ca2N]+·e- with effective electron transfer ability. The consecutive single-electron transfer from inorganic electride [Ca2N]+·e- stabilized free carbanions, which is a key step in achieving the selective reaction. Furthermore, a determinant more important than leaving group ability is the stability control of free carbanions according to the s character determined by the backbone structure. We anticipate that this approach may provide new insight into selective chemical formation, including hydrodehalogenation.

Concentrations, hydrochemistry and risk evaluation of selected heavy metals along the Jimi River and its tributaries at Obuasi a mining enclave in Ghana

Surface water represents significant source of fresh water for irrigation and drinking purposes and therefore preserving the availability and quality of this resource is extremely important. Surface water samples within the catchment area of the Obuasi mine were analysed to assess dissolved concentrations, hydrochemistry, risk evaluation of selected metals and their effects on drinking water quality. Water samples were collected from the Jimi River and its tributaries and analysed for physico-chemical parameters and heavy metals using standard analytical methods. Health risk assessment of As, Pb, Fe, Cd, Ni and Zn based on the average daily dose, hazard quotient and cancer risk was also determined. The results indicated that, most of the physico-chemical parameters are within WHO guidelines except conductivity, turbidity, alkalinity and total hardness. The mean concentrations of heavy metals and ionic dominance pattern follow the order: Cd Mg2+ > K+ > Na+ and HCO3 − > SO4 2+ > Cl−. The health-risk assessment revealed that hazard quotient (HQing) and hazard index (HIing) values were below the acceptable limit, indicating non-carcinogenic risk to the recipient via oral intake and dermal contact of the water. The calculated values for chronical daily intake (CDI) were found in the order of Fe > Zn > As > Pb > Cd > Ni in both adults and children. The carcinogenic risk (CRing) via ingestion route for As, Cd, and Pb were higher than the acceptable limit (10−6). Multivariate statistical analysis results revealed that natural processes and anthropogenic activities were the main sources of water contamination. The results suggested multiple natural processes and anthropogenic activities like mining significantly contribute to the considerable environmental pollution contamination of the Jimi River and its tributaries. Our findings have important public health implications, and we suggest that a system of sentinel surveillance is being implemented that, in turn, can guide adequate responses.

Microbial and chemical contamination of water, sediment and soil in the Nakivubo wetland area in Kampala, Uganda.

The reuse of domestic and industrial wastewater in urban settings of the developing world may harm the health of people through direct contact or via contaminated urban agricultural products and drinking water. We assessed chemical and microbial pollutants in 23 sentinel sites along the wastewater and faecal sludge management and reuse chain of Kampala, Uganda. Water samples were examined for bacteria (thermotolerant coliforms (TTCs), Escherichia coli and Salmonella spp.) and helminth eggs. Physico-chemical parameters were determined. Water, sediment and soil samples and edible plants (yams and sugar cane) were tested for heavy metals. Water samples derived from the Nakivubo wetland showed mean concentrations of TTCs of 2.9 × 105 colony-forming units (CFU)/100 mL. Mean E. coli was 9.9 × 104 CFU/100 mL. Hookworm eggs were found in 13.5 % of the water samples. Mean concentrations of iron (Fe), copper (Cu) and cadmium (Cd) were 21.5, 3.3 and 0.14 mg/L, respectively. In soil samples, we found a mean lead (Pb) concentration of 132.7 mg/L. In yams, concentrations of Cd, chromium (Cr) and Pb were 4.4, 4.0 and 0.2 mg/L, while the respective concentrations in sugar cane were 8.4, 4.3 and 0.2 mg/L. TTCs and E. coli in the water, Pb in soil, and Cd, Cr and Pb in the plants were above national thresholds. We conclude that there is considerable environmental pollution in the Nakivubo wetland and the Lake Victoria ecosystem in Kampala. Our findings have important public health implications, and we suggest that a system of sentinel surveillance is being implemented that, in turn, can guide adequate responses.