Toxics2014, 2(2), 134-157; doi:10.3390/toxics2020134 (doi registration under processing) - published online 17 April 2014 Show/Hide Abstract
Abstract: Bisphenol A (BPA) is used in numerous industrial and consumer product applications resulting in ubiquitous exposure. Children’s exposure is of particular concern because of evidence of developmental effects. Childhood exposure is estimated for different age groups in two ways. The “forward” approach uses information on BPA concentrations in food and other environmental media (air, water, etc.) combined with average contact rates for each medium. The “backward” approach relies on urinary biomonitoring, extrapolating backward to the intake which would have led to the observed biomarker level. The forward analysis shows that BPA intakes are dominated by canned food consumption, and that intakes are higher for younger ages. Mean intake estimates ranged from ~125 ng/kg-day for 1 year-olds to ~73 ng/kg-day among 16–20 years olds. Biomonitoring-based intakes show the same trend of lower intakes for older children, with an estimate of 121 (median) to 153 (mean) ng/kg-day for 2–6 years, compared with 33 (median) to 53–66 (mean) ng/kg-day for 16–20 years. Infant intakes were estimated to range from ~46 to 137 ng/kg-day. Recognizing uncertainties and limitations, this analysis suggests that the “forward” and “backward” methods provide comparable results and identify canned foods as a potentially important source of BPA exposure for children.
Abstract: Perchloroethylene (PCE) is a highly utilized solvent in the dry cleaning industry because of its cleaning effectiveness and relatively low cost to consumers. According to the 2006 U.S. Census, approximately 28,000 dry cleaning operations used PCE as their principal cleaning agent. Widespread use of PCE is problematic because of its adverse impacts on human health and environmental quality. As PCE use is curtailed, effective alternatives must be analyzed for their toxicity and impacts to human health and the environment. Potential alternatives to PCE in dry cleaning include dipropylene glycol n-butyl ether (DPnB) and dipropylene glycol tert-butyl ether (DPtB), both promising to pose a relatively smaller risk. To evaluate these two alternatives to PCE, we established and scored performance criteria, including chemical toxicity, employee and customer exposure levels, impacts on the general population, costs of each system, and cleaning efficacy. The scores received for PCE were 5, 5, 3, 5, 3, and 3, respectively, and DPnB and DPtB scored 3, 1, 2, 2, 4, and 4, respectively. An aggregate sum of the performance criteria yielded a favorably low score of “16” for both DPnB and DPtB compared to “24” for PCE. We conclude that DPnB and DPtB are preferable dry cleaning agents, exhibiting reduced human toxicity and a lesser adverse impact on human health and the environment compared to PCE, with comparable capital investments, and moderately higher annual operating costs.
Abstract: A wide ranging survey was carried out of the available data from ten different countries on human exposure to chlorpyrifos, in many different occupational and nonoccupational settings. Low levels of chlorpyrifos residues were found to be widely distributed in the global human population, but most of these do not constitute a public health risk, as evaluated using the U.S. Environmental Protection Agency (USEPA) Guidelines. For example, the general populations in USA, Germany and Italy had detectable residue levels well below the guidelines. However, high levels of health risk were apparent in a specific group of pregnant mothers in the USA, at median exposure with a HQ0.50 of 26.6, suggesting that most of this population group was affected. Also the high exposure group (5% most exposed) with occupationally exposed manufacturing workers in the USA had a HQ0.95 of 2.6to 42.0, and pest control applicators in Australia and the USA both had a HQ0.95 of 5.2. Some farmers in Sri Lanka and Vietnam had a high level of risk after spraying applications, having a HQ0.95 of 2.2 and 19.5 respectively at the high exposure level. These results suggest that there is a possibility of adverse health effects in specific population groups in many different settings throughout the world.
Abstract: The increasing penetration of materials and products containing engineered nanoparticles (ENPs) to the market is posing many concerns regarding their environmental impacts. To assess these impacts, there is an urgent need of techniques for determining the health-related properties of ENPs and standards for assessing their toxicity. Although a wide number of systems for characterizing nanoparticles in different media (i.e., gases and liquids) is already commercially available, the development of protocols for determining the cytotoxicity of ENPs is still at an infant stage, drawing upon existing knowledge from general toxicology. In this regard, differences in the preparation of ENP-containing solutions for cytotoxicity testing, as well as in the steps involved in the tests can result in significant deviations and inconsistencies between studies. In an attempt to highlight the urgent need for assessing the environmental impacts of nanotechnology, this article provides a brief overview of the existing methods for determining health-related properties of ENPs and their cytotoxicity.
Abstract: Natural uranium is comprised of three radioactive isotopes: 238U, 235U, and 234U. Depleted uranium (DU) is a byproduct of the processes for the enrichment of the naturally occurring 235U isotope. The world wide stock pile contains some 1½ million tons of depleted uranium. Some of it has been used to dilute weapons grade uranium (~90% 235U) down to reactor grade uranium (~5% 235U), and some of it has been used for heavy tank armor and for the fabrication of armor-piercing bullets and missiles. Such weapons were used by the military in the Persian Gulf, the Balkans and elsewhere. The testing of depleted uranium weapons and their use in combat has resulted in environmental contamination and human exposure. Although the chemical and the toxicological behaviors of depleted uranium are essentially the same as those of natural uranium, the respective chemical forms and isotopic compositions in which they usually occur are different. The chemical and radiological toxicity of depleted uranium can injure biological systems. Normal functioning of the kidney, liver, lung, and heart can be adversely affected by depleted uranium intoxication. The focus of this review is on the chemical and toxicological properties of depleted and natural uranium and some of the possible consequences from long term, low dose exposure to depleted uranium in the environment.
Abstract: Within EU marketing authorization procedures of human and veterinary medicinal products (HMP and VMP), an environmental risk assessment (ERA) has to be performed. In the event that an unacceptable environmental risk is identified, risk mitigation measures (RMM) shall be applied in order to reduce environmental exposure to the pharmaceutical. Within the authorization procedures of HMP, no RMM have been applied so far, except for specific precautions for the disposal of the unused medicinal product or waste materials. For VMP, a limited number of RMM do exist. The aim of this study was to develop consistent and efficient RMM. Therefore, existing RMM were compiled from a summary of product characteristics of authorized pharmaceuticals, and new RMM were developed and evaluated. Based on the results, appropriate RMM were applied within the authorization procedures of medicinal products. For HMP, except for the existing precautions for disposal, no further reasonable measures could be developed. For VMP, two specific precautions for disposal and 17 specific precautions for use in animals were proposed as RMM.