Assessing Health Risk Associated with Uranium in Rietspruit Water, Far West Rand Goldfield, South Africa

Uranium, U, as a toxic element has detrimental radiological and chemical impacts on human health when ingested at elevated concentration in water. The establishment of gold mining operations upstream to the Rietspruit is assumed to be a source of uranium into this water body which flows through residential and agricultural land. Water samples from the stream were collected and analysed using inductively coupled plasma mass spectrometry to determine the concentration of U. Uranium concentrations above South African regulatory limit were recorded in the stream water which is used for domestic, agricultural and religious activities as observed during field visits. Results from calculations showed that the maximum annual effective dose within this mining environment was above 1 mSv/year for all age groups. Furthermore, the probability of radiological risk is lower than the chemical risk which is due to the ingestion of U in the Rietspruit water. The chemical risk analysis showed that within 24 km of this mining environment, stream users are in danger of U chemical toxins therefore, it is important to educate the stream users about their health risk of U and recommend adequate interventions by relevant government agencies to this effect.

Assessment of Occupational Risks in the Toxicology and Pharmacology Laboratory Using the FMECA Method

The Toxicology and Pharmacology Laboratory is a high-risk work environment, especially the chemical risk that appears when people are exposed to reagents and chemicals. A corrective approach is required to identify and control these risks. The aim of this study is to determine how to manage the analytical risks at LTP designated for the dosage of drugs and poisons (narcotics, pesticides, mycotoxins, etc.). For this purpose, the risk analysis applying the FMECA method, a risk management tool that aims on the one hand, to qualitatively analyze the process, to analyze the failure modes, the causes and their effects, and to on the other hand, rate the criticality defined by the parameters of frequency of occurrence, severity and detection that will allow a quantitative analysis of each of the failure modes. Thus, the criticality calculation will help to determine the critical risks to be corrected, and to recommend corrective and preventive actions to be implemented within the service.

Weight of Evidence for the Microplastic Vector Effect in the Context of Chemical Risk Assessment

The concern that in nature, ingestion of microplastic (MP) increases exposure of organisms to plastic-associated chemicals (the ‘MP vector effect’) plays an important role in the current picture of the risks of microplastic for the environment and human health. An increasing number of studies on this topic have been conducted using a wide variety of approaches and techniques. At present, the MP vector effect is usually framed as ‘complex’, ‘under debate’ or ‘controversial’. Studies that critically discuss the approaches and techniques used to study the MP vector effect, and that provide suggestions for the harmonization needed to advance this debate, are scarce. Furthermore, only a few studies have strived at interpreting study outcomes in the light of environmentally relevant conditions. This constitutes a major research gap, because these are the conditions that are most relevant when informing risk assessment and management decisions. Based on a review of 61 publications, we propose evaluation criteria and guidance for MP vector studies and discuss current study designs using these criteria. The criteria are designed such that studies, which fulfil them, will be relevant to inform risk assessment. By critically reviewing the existing literature in the light of these criteria, a weight of evidence assessment is provided. We demonstrate that several studies did not meet the standards for their conclusions on the MP vector effect to stand, whereas others provided overwhelming evidence that the vector effect is unlikely to affect chemical risks under present natural conditions.

PFAS and potential adverse impacts on bone and adipose tissue through interactions with PPAR-gamma

Per- and polyfluoroalkyl substances (PFAS) are a widely dispersed, broad class of synthetic chemicals with diverse biological effects, including effects on adipose and bone differentiation. PFAS most commonly occur as mixtures and only rarely, if ever, as single environmental contaminants. This poses significant regulatory questions and a pronounced need for chemical risk assessments, analytical methods, and technological solutions to reduce the risk to public and environmental health. The impacts of PFAS on biological systems may be complex. Each may have several molecular targets initiating multiple biochemical events leading to a number of different adverse outcomes. An exposure to mixtures or co-exposures of PFAS complicates the picture further. This review illustrates how PFAS target peroxisome proliferator activated receptors. Additionally, we describe how such activation leads to changes in cell differentiation and bone development that contributes to metabolic disorder and bone weakness. This discussion sheds light on the importance of seemingly modest outcomes observed in test animals and highlights why the most sensitive endpoints identified in some chemical risk assessments are significant from a public health perspective.