Risk Assessment of Per- and Polyfluoroalkyl Substance Mixtures: A Relative Potency Factor Approach.

Per- and polyfluoroalkyl substances (PFAS) often occur together as contamination in exposure media such as drinking water or food. The relative potency factor (RPF) methodology facilitates the risk assessment of mixture exposure. A database of liver endpoints was established for 16 PFAS, using data with the same species (rat), sex (male), and exposure route (oral) and comparable exposure duration (42-90 d).

Risk management of hazardous substances in a circular economy.

The ambitions for a circular economy are high and unambiguous, but day-to-day experience shows that the transition still has many difficulties to overcome. One of the current hurdles is the presence of hazardous substances in waste streams that enter or re-enter into the environment or the technosphere. The key question is: do we have the appropriate risk management tools to control any risks that might arise from the re-using and recycling of materials? We present some recent cases that illustrate current practice and complexity in the risk management of newly-formed circular economy chains.

Towards sustainable management of groundwater: policy developments in The Netherlands.

This article presents and discusses the main elements for a fundamental policy change for groundwater management in The Netherlands. The study analyzes the status and current use of groundwater, the increasing pressure in The Netherlands and many other countries on the natural soil-water system, the effects on quality and quantity of groundwater and the use of the subsoil. An overview is given of the current national and European regulations regarding groundwater and related policies for e.

Lung cancer risk and past exposure to emissions from a large steel plant.

We studied the spatial distribution of cancer incidence rates around a large steel plant and its association with historical exposure. The study population was close to 600,000. The incidence data was collected for 1995-2006.

Possibilities of implementation of bioavailability methods for organic contaminants in the Dutch Soil Quality Assessment Framework.

In the Netherlands, risk assessment of contaminated soils is based on determining the total contaminant concentration. If this measured soil concentration exceeds the Soil Quality Standards (SQS) a higher tier risk evaluation must be performed. Experiences from the field have given rise to the perception that performing risk evaluations based on (measured) total concentrations may lead to an inaccurate assessment of the actual risks.

Implementation of bioavailability in standard setting and risk assessment.

Bioavailability is, to an increasing extent, recognised as the key issue linking the increased levels of toxicants to actually occurring adverse effects in ecosystems, whilst taking the modifying effects of the abiotic components of the environment into account. Various factors may affect bioavailability in the field, and these factors are often time and space dependent. This is one of the main reasons why legislators have been reluctant to implement bioavailability in risk assessment procedures.

Implementation of bioavailability in standard setting and risk assessment: suggestions based on a workshop with emphasis on metals.

Bioavailability is increasingly recognised as the key issue linking increased levels of toxicants with actually occurring adverse effects in ecosystems, whilst taking the modifying effects of the abiotic components of the environment into account. Various factors may affect bioavailability in the field, and often these factors are time- and space-dependent. This is one of the main reasons why legislators have been reluctant in implementing bioavailability in risk assessment procedures.