The Committee for Medicinal Products for Veterinary Use (CVMP) recently adopted a ‘Guideline on assessing the environmental and human health risks of veterinary medicinal products in groundwater’ (EMA/CVMP/ERA/103555/2015). This will come into force on 1st November 2018. So how will this guideline affect the groundwater assessment of veterinary medicinal products?
The guideline identifies two potential ‘at risk’ groups; humans using groundwater as drinking water and groundwater biota. The risk assessment approach is summarised below:
Human health assessment
The assessment to humans is conducted by comparing the PECgroundwater (PECGW) to the maximum tolerable concentration in drinking water (MTCdw) which is estimated based on a human consuming 2 litres of drinking water where 10% of the acceptable daily intake (ADI) of the substance is taken up in drinking water. Where an ADI hasn’t been set because a substance is considered not to cause a risk to consumers from eating meat, milk and eggs, it is considered not to pose a risk via drinking water. The risk is assessed by comparing the PECGW with the MTCdw and risk quotients below 1 indicate the risk to human health is acceptable.
Groundwater ecosystem assessment
The assessment to groundwater ecosystems involves calculating a PNECgroundwater which is intended to protect vulnerable groundwater biota that may not be able to recover from chemical stressors. As no ecotoxicological studies are available to assess long term effects to groundwater species, the PNECgroundwater is calculated by applying an assessment factor of 10 to the lowest aquatic endpoint in the substance dataset. The risk is assessed by comparing the PECGW with the PNECgroundwater and risk quotients below 1 indicate the risk to groundwater ecosystems is acceptable.
Refinements to PECgroundwater can be considered in the assessment (e.g. use of FOCUS modelling, degradation in manure, animal metabolism) and where risks are not considered acceptable, risk mitigation measures should be proposed or the risk addressed in the benefit/risk analysis.
If you’ve any questions about the new guideline or if you’re interested in our upcoming FOCUS GW and SW training course, please contact Claire.McMillan@cea-res.co.uk.