Arsenic speciation in rice consumed in south-western Nigeria,and estimation of dietary intake of arsenic species through rice consumption

This study determined concentrations and speciation of arsenic (As) in rice samples obtained from the cities of Akure, Ore, Ondo and Ikare in Ondo State, south-western Nigeria. The estimated dietary intake of As from rice consumption for total As and the identified As species were compared with the As benchmark dose lower confidence limit. Analyses of rice from the four cities identified three As species: inorganic As, monomethylarsonic, acid and dimethylarsinic acid. Concentrations of total As and the As species differed significantly across the sampling locations (by a factor of 2.5 for total As). Mean levels (±S.D.) were 58.8 ± 0.7 µg/kg total As, 47.0 ± 0.6 µg/kg inorganic As, 0.33 ± 0.03 µg/kg monomethylarsonic acid, and 11.5 ± 0.1 µg/kg dimethylarsinic acid. The estimated mean dietary intakes were 4.1 µg/d total As, 3.3 µg/d inorganic As, 0.02 µg/d monomethylarsonic acid, and 0.8 µg/d dimethylarsinic acid. These values are below the benchmark dose lower confidence limit and comparable to, or lower than, those reported for other countries. Thus, consumption of rice cultivated in south-western Nigeria does not appear to have inherent As-associated health risks.     

Effects of low doses of glyphosate on DNA damage,cell proliferation and oxidative stress in the HepG2 cell line

Environmental Science and Pollution Research - We studied the toxic effects of glyphosate in vitro on HepG2 cells exposed for 4 and 24 h to low glyphosate concentrations likely to be...     

Source apportionment of settleable particles in an impacted urban and industrialized region in Brazil

Environmental Science and Pollution Research - Settleable particulate matter (SPM), especially coarser particles with diameters greater than 10 μm, has been found culprit of high...     

Airborne polycyclic aromatic hydrocarbons in a medium-sized city affected by preharvest sugarcane burning and inhalation risk for human health

Polycyclic aromatic hydrocarbons (PAHs) in air were measured in a municipality where sugarcane plantations are extensive, at three sites, one in the city center and two in rural localities. Twenty-four-hour sampling was done using PS1 PUF samplers from Andersen Instruments Inc., at least 1 day per month per site, from June 2009 to October 2009. The chemical analyses were performed by gas chromatography–mass spectrometry (GC/MS) for the 16 most toxic PAHs. The incremental lifetime cancer risk (ILTR) by inhalation was determined by the Monte Carlo method for the urban population using Crystal Ball software. The total concentration of the 16 PAHs at all sites varied from 6.2 to 65.7 ng m^?3, with an average of 25.9 ± 18.2 ng m^?3. The average concentrations per site were 14.1 ± 13.0 ng m^?3 at rural site B, 20.7 ± 11.5 ng m^?3 at rural site A, and 36.1 ± 22.7 ng m^?3 at the central site. The cancer risk for infants, children, and adults was approximately 14%, 25%, and 61% of the total IRLT, respectively. The mean (95% upper probability limit [95% UPL]) values were 1.2 × 10^?7 (2.2 × 10^?7) for infants, 2.2 × 10^?7 (4.1 × 10^?7) for children, and 8.9 × 10^?7 (1.1 × 10^?6) for adults. Although the three most abundant PAHs found were phenanthrene, fluoranthene, and pyrene, the three most important contributions to the incremental risk of cancer came from benzo[a]pyrene, benzo[b]fluoranthene, and naphthalene. Compared with the risks in big cities such as São Paulo, this would be low, but not negligible. Analysis of ratios of PAHs according to the literature showed that vehicle exhaust and biomass burning, including sugarcane burning, seem to be the most important contributors to PAH concentrations in the central area of Araraquara City.

Implications:The growth of biofuel use worldwide, especially ethanol, together with preharvesting burning practice, is cause of concern with regard to possible health effects, due to increased air pollution levels in cities in regions where sugarcane plantation and processing are intensive. This paper shows that the risk of cancer from PAH inhalation in an urban area surrounded by sugarcane agriculture was of the same order of magnitude as the tolerable risk value of 10^?6. As other classical and hazardous pollutants are also present, care should be taken to keep pollution as low as possible to protect human health.     

Sugar beet ( L.) growth reduction caused by hydrochar is related to nitrogen supply

Hydrothermal carbonization allows rapid conversion of biomass into a carbon-rich, lignite-like product (hydrochar). It is assumed to have beneficial effects on soil properties and plant growth, but detailed studies are lacking, especially in the field. The objective of our study was to investigate the effect of hydrochar incorporated into arable soils on soil mineral nitrogen (N) content and sugar beet growth. In 2010-2011, a field and a pot trial were conducted. Hydrochars (field: 10 Mg ha; pot: equivalent to 30 Mg ha) processed from sugar beet pulp (HSP) and beer draff (HBD) were tested against an untreated control. As a second factor, mineral nitrogen (N) fertilizer level (field: 0, 50, 100, 150 kg N ha; pot: 0, 100, 200 mg N kg soil) was varied. In both trials, hydrochars reduced initial sugar beet growth, especially when hydrochar with a high C/N ratio (38, HSP) was combined with a low N fertilizer level; high N supply partly compensated for the reduced seedling growth. Without N fertilization, no extractable N was present at the end of the pot trial in the HSP treatment, whereas in HBD even more N was extracted than in the control. This suggests remineralization of previously immobilized N when hydrochar with a low C/N ratio was applied (16, HBD). In the field, beet yield was equal at the high N fertilizer level in HSP and at all N levels in HBD treatment. Our results suggest that hydrochar can decrease plant-available N due to N immobilization. Other potential causes for the observed early growth reduction need to be studied more in detail.     

Solar-driven photocatalytic treatment of diclofenac using immobilized TiO<Subscript>2</Subscript>-based zeolite composites

The study is aimed at evaluating the potential of immobilized TiO₂-based zeolite composite for solar-driven photocatalytic water treatment. In that purpose, TiO₂-iron-exchanged zeolite (FeZ) composite was prepared using commercial Aeroxide TiO₂ P25 and iron-exchanged zeolite of ZSM5 type, FeZ. The activity of TiO₂-FeZ, immobilized on glass support, was evaluated under solar irradiation for removal of diclofenac (DCF) in water. TiO₂-FeZ immobilized in a form of thin film was characterized for its morphology, structure, and composition using scanning electron microscopy/energy-dispersive x-ray spectroscopy (SEM/EDX). Diffuse reflectance spectroscopy (DRS) was used to determine potential changes in band gaps of prepared TiO₂-FeZ in comparison to pure TiO₂. The influence of pH, concentration of hydrogen peroxide, FeZ wt% within the composite, and photocatalyst dosage on DCF removal and conversion efficiency by solar/TiO₂-FeZ/H₂O₂ process was investigated. TiO₂-FeZ demonstrated higher photocatalytic activity than pure TiO₂ under solar irradiation in acidic conditions and presence of H₂O₂.     

Modeling integrated urban water systems in developing countries: case study of Port Vila,Vanuatu

Developing countries struggle to provide adequate urban water services, failing to match infrastructure with urban expansion. Despite requiring an improved understanding of alternative infrastructure performance when considering future investments, integrated modeling of urban water systems is infrequent in developing contexts. This paper presents an integrated modeling methodology that can assist strategic planning processes, using Port Vila, Vanuatu, as a case study. 49 future model scenarios designed for the year 2050, developed through extensive stakeholder participation, were modeled with UVQ (Urban Volume and Quality). The results were contrasted with a 2015 model based on current infrastructure, climate, and water demand patterns. Analysis demonstrated that alternative water servicing approaches can reduce Port Vila’s water demand by 35 %, stormwater generation by 38 %, and nutrient release by 80 % in comparison to providing no infrastructural development. This paper demonstrates that traditional centralized infrastructure will not solve the wastewater and stormwater challenges facing rapidly growing urban cities in developing countries.     

Newborns and low to moderate prenatal environmental lead exposure: might fathers be the key?

This study is part of the BioMadrid Project, a bio-monitoring study designed to assess pollutants in the environment surrounding children born in the Madrid region. Our aim in this report is to evaluate the association between prenatal lead exposure and fetal development using three biological samples (maternal and paternal blood lead at around 34 weeks of gestation as well as cord blood lead levels), three biomarkers of effect in cord blood peripheral lymphocytes (micronucleus in binucleated cells, nucleoplasmic bridges, and nuclear buds), and different anthropometrical characteristics at birth. Maternal and cord blood lead were not associated with newborn measurements or genotoxicity biomarkers. In contrast, increases in father blood lead were coupled with lower weight (mean difference (MD), ?110.8 g; 95 % confidence intervals (95%CI), ?235.6 to 6.00; p?<?0.10) and shorter abdominal (MD, ?0.81 cm; 95%CI, ?1.64 to 0.00; p?<?0.05) and cephalic (MD, ?0.32 cm; 95%CI, ?0.65 to 0.00; p?<?0.05) circumferences at birth as well as with the presence of nucleoplasmic bridges (odds ratio, 1.03; 95%CI, 1.00 to 1.06; p?<?0.05) and nuclear buds (odds ratio, 1.02; 95%CI, 0.99 to 1.04; p?<?0.10). These associations were mainly confined to female babies, in whom paternal lead was also inversely associated with length. Our results support the hypothesis that paternal lead exposure may be affecting the development of newborns.     

Biological activity in metal-contaminated calcareous agricultural soils: the role of the organic matter composition and the particle size distribution

Organic matter (OM) plays a key role in microbial response to soil metal contamination, yet little is known about how the composition of the OM affects this response in Mediterranean calcareous agricultural soils. A set of Mediterranean soils, with different contents and compositions of OM and carbonate and fine mineral fractions, was spiked with a mixture of Cd, Cu, Pb, and Zn and incubated for 12 months for aging. Microbial (Biolog Ecoplates) and enzyme activities (dehydrogenase, DHA; β-galactosidase, BGAL; phosphatase, PHOS; and urease, URE) were assessed and related to metal availability and soil physicochemical parameters. All enzyme activities decreased significantly with metal contamination: 36–68 % (DHA), 24–85 % (BGAL), 22–72 % (PHOS), and 14–84 % (URE) inhibitions. Similarly, catabolic activity was negatively affected, especially phenol catabolism (～86 % compared to 25–55 % inhibition for the rest of the substrates). Catabolic and DHA activities were negatively correlated with ethylenediaminetetraacetic acid (EDTA)-extractable Cd and Pb, but positively with CaCl₂, NaNO₃, and DTPA-extractable Cu and Zn. Soluble OM (water- and hot-water-soluble organic C) was positively related to enzyme and catabolic activities. Recalcitrant OM and fine mineral fractions were positively related to BGAL and PHOS. Conversely, catabolic activity was negatively related to clay and positively to silt and labile OM. Results indicate that the microbial response to metal contamination is highly affected by texture and OM composition.     

Effect of water composition on the photocatalytic removal of pesticides with different TiO2 catalysts

The objective of this work is double—firstly to explore the photocatalytic efficiency of five different commercial TiO₂ catalysts in the photodegradation of a mixture of pesticides classified by the EU as priority pollutants and secondly to analyze the correlation between their physicochemical properties and the inhibition of the studied photocatalytic process when natural water was employed. Photocatalytic efficiencies when ultrapure water was used seem to point out that surface area was not a prerequisite for the photodegradation of the selected mixture of pesticides. On the other hand, significant differences in total organic carbon (TOC) conversions were obtained with the two studied water compositions. On one side, Evonik materials appear to be mostly inhibited when natural water was employed, whereas on the other, it should be remarked that anatase Sigma-Aldrich (SA) and, particularly, Hombikat UV100 (HBK) materials presented a very limited photo-efficiency inhibition or even a higher initial rate of TOC removal when a natural water matrix was used, probably due to their specific surface properties (PZC, S _BET). Therefore, heterogeneous photocatalysis has proved to be a promising technology for the degradation of the selected mixture of pesticides where the final photo-efficiency of the five commercial titania catalysts studied here responds to a complex balance between its surface and structural properties.