Background. Lead poisoning is a great public health concern in the Nigerian state of Zamfara due to widespread gold ore mining by artisan miners using rudimentary and unsafe processing techniques. Children aged ≤6 years are especially vulnerable to lead poisoning, which accounts for 0.6% of the global burden of disease. We undertook this study to find out the prevalence and determinants of childhood lead poisoning in Kawaye, a village located in Zamfara’s Anka local government area (LGA). Methods. We conducted a cross-sectional study in April 2013. Using simple random sampling technique, 307 eligible children aged ≤6 years were recruited. Data were collected using interviewer-administered semi-structured questionnaires. Blood specimens were collected via venous draw for blood lead level (BLL) assessment and soil at individual households was tested for presence of lead contamination using a portable X-ray fluorescence spectrometer. Statistical tests of Chi-square and multivariable logistic regression analyses were performed to evaluate factors potentially associated with elevated childhood BLL (≥5 μg/dL). Results. A total of 307 children ≤6 years old were sampled, with males constituting 51% of the total (171). Mean age of children = 38.5 months ± 18.5 SD. Parents/guardians of the studied children were predominantly farmers (37%) and miners (15%), with 53.7% having some informal education while 4.2% had no education. Processing of ore within the living compound was reported by 4% of the miners; 7.5% returned home wearing working clothes; 7.2% brought tools home. Thirty percent of parents/guardians were living below the poverty line. The prevalence of lead poisoning (BLL ≥5 μg/dL) among the children studied was 92.5%, with 34 children (11.1%) having BLL ≥45 μg/dL. Fourteen percent of the households had soil lead levels >400 mg/kg. Being age 24–35 months, having childhood anemia, using kohl eye cosmetic and the combination of father’s/guardian’s low level of education and low socioeconomic status were found to be significant risk factors associated with childhood lead poisoning in the regression analyses. Conclusions. The prevalence of childhood lead poisoning was high in Kawaye, which may be attributable to widespread unsafe mining and ore processing activities in the community. We recommended beginning treatment in all cases where severe lead poisoning was identified, and that further targeted interventions should be designed to address the identified risk factors in order to control and prevent further lead poisoning in the village and the state at large. Competing Interests. The authors declare no competing financial interests.

Background. Elevated concentrations of heavy metals in soil have detrimental consequences on the environment, which translates into damaging effects on humans. Objective. An evaluation was carried out to determine the concentrations of seven heavy metals (As, Cd, Cr, Cu, Hg, Pb, Zn) in soil sediments collected from 12 different stations within the Benya Lagoon in Komenda Edina Eguafo Abrem Municipality (KEEA) in Ghana. Methods. The calibration and concentration measurements of the elements were carried out using a fast sequential hydride generation atomic absorption spectrophotometer. Results. An assessment according to metal concentration in terms of abundance found that Pb registered the highest, while a comparison with standard sediment criteria by USEPA and CBSQG indicated heavy pollution levels of As, Cd, Hg, and Pb. Using Pearson's coefficient matrix, As-Cd had a correlation of 1.000, while Zn-Pb registered 0.858, indicating the same or similar source input for each pair. Both the geo-accumulation index (Igeo) and the contamination factor (CF) gave the extent of contamination in the order Cd > Pb > As > Hg > Cu > Cr > Zn, while the degree of contamination Cd at the stations was in the order 1 > 3 > 4 > 5 > 6 > 2 > 7 > 8 > 9 > 10 > 12 > 11, indicating Station 1 as the most polluted. The Hakanson index established the order of decreasing threat of a potential ecological risk as Cd > Hg > As > Pb > Cu > Cr > Zn. Discussion. The high sums of the individual potential risks values obtained at the sampling stations point to a possible detrimental effect on the health of inhabitants that use resources directly from the lagoon without treatment, and therefore the need for education to curtail any unanticipated disasters. Competing Interests. The authors declare no competing financial interests.

Background. The present investigation was undertaken to study the persistence of pyrimethanil in strawberries and cucumbers following good agricultural practices under field conditions. A secondary objective was to validate a quick, easy, cheap, effective, rugged and safe (QuEChERS) method for the determination of pyrimethanil levels in strawberries and cucumbers using high performance liquid chromatography with photodiode array detection. Methods. Pyrimethanil (20% wettable power (WP)) was sprayed on strawberries and cucumbers grown under field conditions at the dosage recommended by the manufacturer. The dissipation rates of pyrimethanil were described using first-order kinetics and its half-life was 2.9 days in strawberries and 2.2 days in cucumbers. A risk assessment was performed using the risk quotient (RQ). Results. At fortification levels of 0.05, 0.1 and 0.5 mg/kg in strawberries and cucumbers, recoveries ranged from 90.1 to 109% with a relative standard deviation (RSD) ranging from 2.0–7.9%, which is within the acceptable limits for routine analysis of pyrimethanil residues. The limit of quantification (LOQ) was established at 0.05 mg/kg. The results showed that the RQ value was significantly lower than 1. Conclusions. The results of the present study suggest that the risk of pyrimethanil use in strawberries and cucumbers at the recommended dosage is negligible to humans. This study could provide guidance for the safe and reasonable use of pyrimethanil in strawberries and cucumbers to prevent health problems in consumers. Competing Interests. The authors declare no competing financial interests.

The current concept of “effective dose” is not universally safe and could have an important impact on public health. Setting norms and standards for radiation will be much simpler and stricter when they are based on actual, physically measured levels of radionuclides in the body (Bq/kg) and the environment (Bq/m2). Such new standards should correspond to the actual level of anthropogenic radioactive contamination. Analysis of the existing health impact from low-level irradiation leads to the conclusion that the basic level of radiation safety should be within the range of 500–5000 Bq/m2 for additional external γ-emission and 10–100 Bq/kg for additional internal γ-emission. Competing Interests. The author declares no competing financial interests.

Background. Fish advisories have been established by some nations to protect the public from the potentially harmful health effects linked to eating contaminated fish. Advisories are based on estimations of the health risks associated with concentrations of contaminating chemicals found in fish, and the average levels of consumption of fish in the population. Fish is an important source of nutrition in Ghana; however, little is known about the possible health effects associated with metal concentrations found in fish. Objective. The overall aim of the present study was to estimate metal concentrations in fishery resources so as to inform guidelines on fish consumption. Methods. We collated previously published data on levels of metals in fish in Ghana. We also estimated the potential for adverse health effects by calculating a hazard quotient (HQ) based on the reported levels of mercury in fish and either the United States Environmental Protection Agency (USEPA) Reference Dose (RfD) or the FAO/WHO Expert Committee on Food Additives Provisional Tolerable Weekly Intake (PTWI). Both are estimates of methylmercury exposure that is considered safe (0.0001 mg/kg body weight (bw) per day and 0.0016 mg/kg bw/week, respectively). We also compared HQ estimates across different fish species and water bodies in Ghana. Results. Mercury was the only metal for which there was sufficient data to estimate the possible adverse health effects from eating fish caught in Ghana. The mean concentration of mercury was 0.10 mg/kg (± 0.15) wet weight (N= 63 fish samples). This concentration was associated with a HQ of less than 1 when using the Joint FAO/WHO PTWI, but above 1 when using the USEPA RfD. Higher concentrations of mercury (Hg) were detected in fish collected from rivers in gold mining areas of Ghana (0.25 mg/kg ww ±0.23) versus fish collected from lakes/reservoirs (0.04 mg/kg w.w ±0.04) and marine areas (0.06 mg/kg w.w ±0.04). Conclusions. These results suggest regular monitoring of fish collected from water bodies in gold mining regions is warranted. Results also suggest that regulatory bodies may want to consider the development of guidelines for fish consumption advisories when warranted, and remediation of primary sources of mercury contamination to optimize the health benefits of fish consumption. Competing Interests. The authors declare no competing financial interests.

Recycling irrigation water is a common practice at ornamental plant nurseries for conserving water; however, it poses the risk of sourcing and dispersing waterborne plant pathogens, especially species of Phytophthora. Slow sand filtration is a water treatment process that can remove pathogens from water, but the slow rate of water treatment may limit its application at nursery operations. In this study, four novel substrates (crushed brick, calcined clay, polyethylene beads, and Kaldnes® medium) in addition to sand were examined to determine how effective each substrate was at removing zoospores of Phytophthora nicotianae from water. The effects of substrate physical parameters, substrate depths (0, 5, 10, 20, 40, and 60 cm), and microbe density (after nursery effluent was recirculated through each substrate for 21 days) on zoospore removal by each substrate were quantified. Sand was the most effective physical filter and supported development of the best biological filter for removing zoospores. Sand columns 40 and 60 cm deep removed zoospores completely using physical filtration alone, and zoospore removal by sand at 10- and 20-cm depths was increased with the addition of biological filtration. Kaldnes® medium and polyethylene beads were the least effective filtration substrates under all conditions tested. After 21 days of recirculating nursery effluent through substrate columns, microbe density in and zoospore removal by all substrates increased. With further optimization, crushed brick may have potential to be utilized as a recycled material for a slow filtration system focused on removing plant pathogens from irrigation water.

Mineral dissolution plays an essential role in controlling geogenic arsenic (As) contamination in groundwater. Although reductive dissolution of Fe oxyhydroxides is generally considered a key As release mechanism in many aquifers, some recent studies argue that silicate minerals, normally considered “inert” in As release, are the primary source of As contamination under certain conditions. The objective of this study is to determine As distribution in different minerals in a natural sediment and identify As release mechanisms and the role of silicate minerals in As release. A sediment sample was collected, characterized, and tested using leaching experiments at a range of pH and redox potentials. Our results showed that silicate minerals, which make up the bulk of the sediment, are the main As reservoir, containing 75 % of As. Fe–Mn oxyhydroxides, which are minor components in the sediment, are the second largest As reservoir and hold 16 % of As. Leaching experiments showed that silicate mineral dissolution is an important As-releasing mechanism and that high pH and low redox potential promoted silicate mineral dissolution and As release.

The extent of endosulfan sulfate removal from soils by different planting pattern with sweet corn (Zea mays), cowpea (Vigna sinensis), and cucumber (Cucumis sativus) either cultivated alone or together was investigated in pot experiments. Endosulfan sulfate was removed to the greatest extent in the treatment in which sweet corn was grown alone; only 11.3 and 27.2 % of the initial endosulfan sulfate remained in rhizospheric and bulk soil, respectively, of sweet corn grown alone at day 60. Endosulfan sulfate was also removed from soil to a great extent in treatments where cucumber or cowpea was grown alone; only 30.3 and 38.8 % of endosulfan sulfate remained in their respective rhizospheric soil after 45 days. However, cucumber did not tolerate the toxicity of endosulfan sulfate well and died around 50–55 days when it was cultivated either alone or together with another plant. Cultivation of sweet corn and cowpea together was less effective in removing endosulfan sulfate from soil; about 41.7 and 52.3 % of endosulfan sulfate remained in their respective rhizospheric soils after 60 days. The results showed that single cultivation of the plants was the most efficient way to remediate endosulfan sulfate-contaminated soil in this study. Endosulfan sulfate was detected in both the root and shoot of plants but given the low levels found, bioaccumulation was judged to be a relatively minor factor in endosulfan sulfate removal from soil.

The paper reports ultraviolet matrix-assisted laser desorption/ionization mass spectroscopy (UVMALDI-MS) protocol for determination of complex heterogeneous emulsion or suspension formulations. The active agents and surfactants are morpholine fungicide fenpropimorph (1), amorolfine (2), tridemorph (mixture of 2,6-dimethyl-4-alkylmorpholins 3–6), 2,6-dimethyl-4-[2-methyl-3-(6-methyl-decahydro-naphthalen-2-yl)-propyl]-morpholine (7), dodemorph (8), main metabolite of 1 fenpropimorph acid (9), sodium dodecyl sulfate (10), and stearate (11). The full method and techniques validation as well as method performance parameters are discussed in terms of their maximal representativeness toward real environmental and foodstuff assay problems. These are additionally complicated by heterogeneous laterally, vertically, and time distribution of pesticide contaminants and their major metabolites in environmental samples. The real environmental heterogeneous distribution is elucidated, studying sterilized soil fractions with particle size 2.0 μm, clay content 11.5 %, silt 23.0 %, sand 8.1 %, and pH ∈ 6.0–8.1. A statistical sampling cluster approach is used. The method performance parameters are concentration LODs of 0.026 mg kg⁻¹(res. LOQs 0.08666 mg kg⁻¹). Concentration linear dynamic ranges are ∈ 0.025–7.3 mg kg⁻¹(r² = 0.99822 and 0.99421) and ∈ 2.3–7.4 mg kg⁻¹(level of confidence of 99.33₁ %) for complex spiked heterogeneous soil samples. The data illustrates the great capability of method and its promising application for environmental contamination monitoring and controlling programs for assessment.

Plants of the black nightshade (Solanum nigrum L.) Korean ecotype were exposed to a gradient of cadmium (Cd) concentrations (0, 10, 30, 50, and 80 mg kg⁻¹of dry sand). The results showed a significant (p < 0.05) reduction in biomass, root-shoot length, and chlorophyll contents in the plants exposed to Cd compared to the control. Cd concentrations significantly increased in different parts of the plants as indicated by inductively coupled plasma mass spectrometry (ICP-MS) analysis. The amount of Cd accumulated by the plants in the leaves, stems, and roots was 307, 1536, and 3163 mg kg⁻¹of dry matter, respectively, when treated with Cd 80 mg kg⁻¹. The translocation factor (TF) declined with higher Cd concentrations, whereas the bioconcentration factor (BCF) increased with elevated Cd levels. The response to oxidative stress induced by Cd was modulated by the enzymatic activity of peroxidase and polyphenol peroxidase. In terms of non-enzymatic antioxidant biochemicals such as reduced glutathione and polyphenols, its contents in the leaves significantly increased in a dose-dependent manner. The overall increased antioxidant defense response in leaves might have contributed to the higher accumulation and tolerance of plants against Cd-induced oxidative stress. The Korean ecotype of S. nigrum has potential phytoremediation utility for phytostabilization of Cd-contaminated marginal land. However, further genomic insights could contribute to the identification of potential Cd translocation genes.