Minimizing the exposure risk from groundwater pollution by optimizing the temporal extraction patterns

Optimization models for minimizing pollutant exposure from groundwater resources require time and resources that many communities might not have ready access to due to their economic conditions. In such cases, it might be useful to develop a "rule of thumb" approach for suggestions in case of uncertainties and inadequate means to address these uncertainties. Monte Carlo analysis was performed for a simplified groundwater system, and the effects of temporal extraction patterns, distance to the pollution source, dispersivity, pollutant pulse period, pore water velocity, and decay were examined for minimizing the high pollutant exposure risk from the extracted groundwater. Results indicate that, in a high uncertainty scenario, the best bet for minimizing the risk of high pollutant exposure would be to adopt a frequent temporal extraction pattern and supply the water as a mixture of extractions from multiple wells spread over an area. These findings can be used as a "rule of thumb" wherever time and resources might be the limiting factors.

Application of selected life cycle occupational safety methods to the case of electricity production from pyro-oil

Life cycle thinking is a necessary component in preventing the shifting of burden along the life cycle and from one impact category to another. For this reason, many have focused on integrating life cycle thinking into occupational risk assessment. The resultant methods have different properties in terms of scope and outcomes. Literature has been reviewed for life cycle occupational risk assessment methodologies, and 3 methods (life cycle inherent toxicity (LCIT) method, work environment characterization factors (WE-CFs) method, and life cycle risk assessment (LCRA) method) have been selected and applied in a case study of electricity production from pyro-oil to identify suitability and research gaps in the existing literature. The results of the LCIT method were highly heterogenous over life cycle of electricity production. For the current case, the major cancer and non-cancer impacts originated from the same life cycles. The results from WE-CFs method were highly heterogenous over the life cycle of electricity production as well. Agriculture contributed the most to the occupational risks. In the LCRA method, averaging caused the information about the frequency of the risks over life cycle to be lost. The method showed the well-known bargaining between accuracy and simplicity when complex systems are considered. Results from this method were quite homogenous among life cycles, due to the averaging effect. Detailed reporting and follow-up of the worker health issues can enable a more accurate application of the WE-CFs method. The overall results showed that it was possible to apply these 3 methodologies for the EU-28 region.

Environmental impact assessment model for substitution of hazardous substances by using life cycle approach

Regulations that are indirectly driving the substitution of hazardous chemicals, such as the EU REACH regulation, necessitate improvements in chemical alternatives assessment frameworks. In those frameworks, life cycle thinking lacks some important aspects such as systematic and quantitative occupational safety methods and risks from intermediate chemicals that are not released to the environment under normal operating conditions. Concerns of companies about regulatory drivers regarding substances of very high concern often lead to inadequate evaluation of the baseline situation; an issue also overlooked by the frameworks. Moreover, life cycle assessment is optional for assessors with limited resources, such as small and medium enterprises. However, the success of substitution should not be evaluated without life cycle concerns. An environmental impact assessment model has been suggested to overcome these shortcomings of the chemical alternatives assessment frameworks. The model was applied to a case study of primed metal sheet production, where the company was driven to substitute reprotoxic 2-methoxypropanol used in their formulations. The results show that the proposed model is promising for solving the mentioned shortcomings, informing the assessor about substances of very high concern along the life cycle, and it has the potential to be further improved with the help of supporting software and databases. Particularly, in the occupational safety area that concerns risks of accidents at work, improvements to the EU occupational health database can drastically increase the accuracy of the assessments. Besides, the development of methodologies for the quantification of the impacts of reprotoxic, bioaccumulative and endocrine disruptor substances is necessary.