Impact of lime-stabilized biosolid application on Cu,Ni, Pb and Zn mobility in an acidic soil

A soil column leaching study was conducted on an acidic soil in order to assess the impact of lime-stabilized biosolid on the mobility of metallic pollutants (Cu, Ni, Pb and Zn). Column leaching experiments were conducted by injecting successively CaCl₂, oxalic acid and ethylenediaminetetraacetic acid (EDTA) solutions through soil and biosolid-amended soil columns. The comparison of leaching curves showed that the transport of metals is mainly related to the dissolved organic carbon, pH and the nature of extractants. Metal mobility in the soil and biosolid-amended soils is higher with EDTA than with CaCl₂ and oxalic acid extractions, indicating that metals are strongly bound to solid-phase components. The single application of lime-stabilized biosolid at a rate ranging from 15 to 30 t/ha tends to decrease the mobility of metals, while repeated applications (2?×?15 t/ha) increase metal leaching from soil. This result highlights the importance of monitoring the movement and concentrations of metals, especially in acid and sandy soils with shallow and smaller water bodies.     

Low-dose aspirin for prevention of adverse outcomes related to abnormal placentation

Meta-analysis of randomized studies on the use of low-dose aspirin in women at high risk of preeclampsia (PE) has demonstrated that if treatment is initiated at ≤16 weeks' gestation, there is significant reduction in the risk of PE [relative risk (RR) 0.47, 95% confidence interval (CI) 0.36–0.62], fetal growth restriction (RR 0.46, 95% CI 0.33–0.64), preterm birth (RR 0.35, 95% CI 0.22–0.57) and perinatal death (RR 0.41, 95% CI 0.19–0.92), whereas the effect of treatment after 16 weeks is substantially less (RR 0.78, 95% CI 0.61–0.99; RR 0.98, 95% CI 0.88–1.08; RR 0.90, 95% CI 0.83–0.97; and RR 0.93, 95% CI 0.73–1.19, respectively). Moreover, the decrease in the risk of PE from early onset treatment seems to be related to the dose of aspirin, and a dose of >80 mg daily should be considered for optimal benefits. © 2014 John Wiley & Sons, Ltd.     

Use of a low-cost biosorbent to remove pesticides from wastewater

A lignocellulosic substrate (LS) obtained from our local agroindustry was used as a low-cost and effective adsorbent for the removal of pesticides from wastewaters. The studied pesticides were terbumeton (N-(1,1-dimethyl)-Nethyl-6-methoxy-1,3,5-triazine-2,4-diamine), desethyl terbumeton (N-(1,1-dimethylethyl)-6-methoxy-1,3,5-triazine-2,4-diamine), dimetomorph (4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)acryloyl]morpholine), and isoproturon (3-(4-isopropylphenyl)-1,1-dimethylurea). Batch and column experiments were conducted as a function of pH and pesticide concentration under laboratory and industrial conditions. The concentration range studied for the pesticides varied from 2 x 10(-7) to 3 x 10(-4) mol L(-1). The influence of organic and inorganic pollutants was assessed by studying the retention of pesticide in the presence of copper(II) and a surfactant. These experiments indicated that LS is an efficient adsorbent toward the investigated pesticides and has little influence of the other pollutants. The kinetic adsorptions are fast, and the amounts of adsorbed pesticide varied from 1 to 8 g kg(-1) of LS. These retention capacities show that LS can provide a simple, effective, and cheap method for removing pesticides from contaminated waters. Thus, this biomaterial may be useful for cleaning up polluted waters.     

Ecotoxicological assessment of TiO2 byproducts on the earthworm Eisenia fetida

The increasing production of nanomaterials will in turn increase the release of nanosized byproducts to the environment. The aim of this study was to evaluate the behaviour, uptake and ecotoxicity of TiO₂ byproducts in the earthworm Eisenia fetida. Worms were exposed to suspensions containing 0.1, 1 and 10 mg/L of byproducts for 24 h. Size of TiO₂ byproducts showed aggregation of particles up to 700 μm with laser diffraction. Only worms exposed at 10 mg/L showed bioaccumulation of titanium (ICP-AES), increasing expression of metallothionein and superoxide dismutase mRNA (Real-time PCR) and induction of apoptotic activity (Apostain and TUNEL). TiO₂ byproducts did not induce cytotoxicity on cœlomocytes, but a significant decrease of phagocytosis was observed starting from 0.1 mg/L. In conclusion, bioaccumulation of byproducts and their production of reactive oxygen species could be responsible for the alteration of the antioxidant system in worms.     

Community-company relations in gold mining in Ghana

As a result of Structural Adjustment Programme from the 1980s, many developing countries have experienced an increase in resource extraction activities by international and transnational corporations. The work reported here examines the perceived impacts of gold mining at the community level in the Wassa West District of Ghana, Africa and discusses those perceived impacts in the context of globalization processes and growing multinational corporate interest in Corporate Social Responsibility (CSR). Interview data compared community members' perceptions with those of company representatives in three communities. The results indicate that communities held companies responsible for a series of economic, social, and environmental changes. While recognizing some of the benefits brought by the mines, communities felt that the companies did not live up to their responsibility to support local development. Companies responded by denying, dismissing concerns, or shifting blame. Findings from this work show that lack of engagement and action by government agencies at all levels resulted in companies acting in a surrogate governmental capacity. In such situations, managing expectations is key to community-company relations.     

Disclosure of stigmatized identities at work: An interdisciplinary review and agenda for future research

This review focuses on the disclosure decisions faced by employees with concealable stigmatized identities—one of the most challenging decisions these individuals must make on a day-to-day basis. Indeed, multiple theoretical frameworks have provided a foundation for understanding the antecedents and outcomes associated with the decision to disclose or not to disclose a stigmatized identity. What is less clear, however, is the extent to which these frameworks have been empirically supported. This systematic review serves to unify the extant literature and prompt continued research related to employees with concealable stigmatized identities. Specifically, we draw upon multiple fields of study, including applied psychology, management, social psychology, and occupational health as a means to systematically synthesize the existing empirical research related to disclosure of stigmatized identities at work. In addition to advancing the scholarly knowledge of disclosure, this review also provides practical utility to organizations as they continue to create work environments that foster inclusion of all stigmatized and nonstigmatized employees.     

Metal binding properties of extracellular polymeric substances extracted from anaerobic granular sludges

Extracellular polymeric substances (EPS) were extracted from four anaerobic granular sludges with different procedures to study their involvement in biosorption of metallic elements. EPS extracts are composed of closely associated organic and mineral fractions. The EPS macromolecules (proteins, polysaccharides, humic-like substances, nucleic, and uronic acids) have functional groups potentially available for the binding of metallic elements. The acidic constants of these ionizable groups are: pK _a1 (4–5) corresponding to the carboxyl groups; pK _a2 (6–7) corresponding to the phosphoric groups; pK _a3 (8–10) and pK _a4 (≈10) corresponding to the phenolic, hydroxyl, and amino groups. The polarographic study confirms the higher affinity of the EPS to bind to lead than to cadmium. Moreover, the binding of these metallic compounds with the EPS is a mix of several sorption mechanisms including surface complexation, ion exchange, and flocculation. Inorganic elements were found as ions linked to organic molecules or as solid particles. The mineral fraction affects the binding properties of the EPS, as the presence of salts decreases the EPS binding ability. Calcite and apatite particles observed on SEM images of EPS extracts can also sorb metallic elements through ion exchange or surface complexation.     

Blood Pb Levels in pregnant Nigerian women in Abakaliki, South-Eastern Nigeria

Environmental lead (Pb) exposure and toxicity have been recognised as public health problems of global importance, affecting both the developed and developing nations. In this work, blood Pb of pregnant women that were not exposed to lead by their occupation (n?=?349), with mean ± SD age of 27.0?±?4.8 years and gestational age of 21.8?±?3.1 weeks at recruitment were determined using atomic absorption spectrophotometer. The results showed that 309 (88.5 %) of the women had a mean?±?SD blood Pb of 40.0?±?16.5 μg/dl, which is higher than the current US Centre for Disease Prevention and Control action limit (>10 μg/dl). The observed high prevalence of elevated blood Pb levels may be related to maternal low socioeconomic status. Health education is, therefore, urgently needed to sensitise the general public and the policy makers of the level of Pb exposure in Abakaliki environment and the inherent health implications. In addition to mandatory environmental lead monitoring, blood Pb screening for would-be mother is recommended, and those whose blood Pb are found elevated should be appropriately treated.