This study identifies and analyses the occupational risks associated with solid waste management practices in the informal enterprises of Gweru. Many concerns have been raised about the potential harm from waste to the environment and the general public, but the risks and consequent costs of occupational hazards in waste management have received little attention in the rush to adopt or adapt te...

Schizophrenia: A Plausible Neurobiologic Connection In their article in the April issue of EHP, Opler et al. (2004) raise the intriguing possibility that prenatal exposure to the ubiquitous developmental neurotoxicant lead (Pb2+) may be associated with schizophrenia, an adult psychiatric disease. Although the study has certain limitations that the authors discussed, it brings to light the possi...

A new fluorescent sensor based on rhodamine B for Pb2+ was synthesized. The new fluorescent sensor showed an extreme selectivity for Pb2+ over other metal ions examined in acetonitrile. Upon the addition of Pb2+, an overall emission change of 100-fold was observed, and the selectivity was calculated to be 200 times that of Zn2+. The signal transduction occurs via of reversible CHEF (chelation-e...

We quantitatively modeled the volume phase transition of a hydrogel containing a crystalline colloidal array with a crown ether ligand which binds Pb2+. The hydrogel volume response and the wavelength diffracted depend on the Pb2+ concentration and on both the ionic strength and the valence of the nonbinding ionic species. We successfully modeled the response of this hydrogel Pb2+ sensor to ion...

The 2009/2010 pandemic influenza virus (H1N1pdm) contains an avian-lineage PB2 gene that lacks E627K and D701N substitutions important in the pathogenesis and transmission of avian-origin viruses in humans or other mammals. Previous studies have shown that PB2-627K is not necessary because of a compensatory Q591R substitution. The role that PB2-701N plays in the H1N1pdm phenotype is not well un...

In an effort to better understand the consequences of lead (Pb2+) on skeletal growth, the effects of Pb2+ were investigated using ROS 17/2.8 bone-like cells in vitro. These studies revealed that Pb2+ (4.5 x 10(-6) M -4.5 x 10(-7) M) has little or no effect on cell shape except when added immediately following seeding of the cells. However, proliferation of ROS cells was inhibited, in the absenc...

The aberrant generation of oxygen and nitrogen free radicals can cause severe damage to key cellular components, resulting in cell apoptosis. Similarly, excitotoxicity leads to protease activation and mitochondrial dysfunction, which subsequently causes cell death. Each of these factors play critical roles in the neuronal cell death underlying various neurodegenerative diseases. Procyanidin B2 ...

Growth of the population and of industrialization, and substandard disposal of the increased waste products thus generated, have resulted in numerous documented cases of harm to human, plant, and animal health. The Resource Conservation and Recovery Act (1976), its stated goals, and its intended means of implementation, are discussed relative to hazardous waste problems. Subtitle C of this Act,...

Schizophrenia: A Plausible Neurobiologic Connection In their article in the April issue of EHP, Opler et al. (2004) raise the intriguing possibility that prenatal exposure to the ubiquitous developmental neurotoxicant lead (Pb2+) may be associated with schizophrenia, an adult psychiatric disease. Although the study has certain limitations that the authors discussed, it brings to light the possi...