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anses

French Agency for Food, Environmental and Occupational Health & Safety

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Updated on 04/10/2016

Water and chemical risks

Assessment of health risks related to situations in which some water quality limits or references are exceeded due to the presence of emerging substances.

Keywords : Water, Tap water

Water intended for human consumption comes from ground and surface water which is treated to make it drinkable. Depending on the natural environment from which this water comes, it may contain various natural or man-made chemicals chemicals. Upon a request by the Ministry of Health, ANSES evaluates health risks related to the presence of regulated or unregulated chemicals in water intended for human consumption. A description of this work is given below.

Water intended for human consumption is produced from so-called "raw" ground or surface water which is treated to make it drinkable. Depending on the natural environment from which this water comes it may contain various natural chemicals (aluminium, fluorine, calcium) or man-made substances (drug residues, heavy metals, etc).

In order to protect the health of consumers, maximum concentrations are defined by regulations for certain chemicals found in water distributed to consumers. These values, known as "quality limits", are set so that life-long consumption of water which complies with these criteria will not expose the individual to any health risk. The values known as "quality references" concern substances which cause no direct health effects when found in normal concentrations in water. On the other hand, any excess values of these quality references may indicate an anomaly in water treatment stations and may cause discomfort or other problems for consumers.

Thus, in 1998, the European Directive 98/83/EC on the quality of water intended for human consumption reinforced the preventive health measures by setting new quality criteria for drinking water. This Directive also foresaw the possibility of exceeding these quality limits, when authorised, on condition that:

  • the excess be temporary;
  • measures be taken to restore the quality of the water;
  • there be no other reasonable way of continuing to distribute the water;
  • a temporary limit value be set and applied to ensure that public health is protected during this period.

These new quality requirements and regulations that make it possible to manage situations in which excessive concentrations are observed in water, have been transposed to the French Public Health Code.

The role of ANSES

In order to enable the health authorities to set temporary limits to enable regional health authorities to manage situations of excessive concentrations, the Directorate General for Health made a formal request to the Agency in 2003, asking it to assess, for a series of physical-chemical parameters, the health risks related to the consumption of water in which the concentrations  were greater than the prescribed quality limits or references. The Agency issued an interim report on 16 parameters in 2007. Since then the scientific experts have continued their work and new Opinions have been published

Along with this work done in a regulatory framework, the Agency has for a number of years now been regularly questioned about health risks related to the detection in water intended for human consumption of substances for which no regulatory quality limits have been set (ethyl tert-butyl ether, perchlorates, etc.). The presence of these compounds may be revealed during national sampling and analysis campaigns conducted by the Nancy Laboratory for Hydrology and aimed at classes of substances of concern. The Agency may also asses health risks following a particular local situation in which unregulated pollutants have been measured in distributed water.

The Agency follows the same procedure whether it be to provide expertise on the exceeding of regulatory parameters or of concentrations of unregulated substances, for each physical-chemical parameter studied. Its expertise is based on the analysis of:

  • available data on water contamination,
  • possible sources of water contamination,
  • ways in which water can be treated,
  • other routes of exposure of humans to the substance in question,
  • all of the toxicological and epidemiological data available for characterising the hazard and ultimately the risk to consumers.

The aim is to provide the government authorities with a risk management tool that they can use both when regulatory requirements are exceeded for water intended for human consumption (when waivers to regulatory provisions have been granted), and when dealing with unregulated pollutants. This will then enable the public authorities to take adequate steps to protect the health of populations including, when necessary, restricting or prohibiting use of water for all or part of the population.

All of this work concerning both regulated substances and emerging substances will enable France to play a significant role in the possible revision of the European Directive 98/83/EC on the quality of water intended for human consumption.

Focus on drug residues

The French national plan for dealing with drug residues in water (PNRM) was drawn up in 2011, following the first French National Environment and Health Action Plan from 2004-2008 (PNSE 1 or NEHAP 1) and was then included in the second plan (PNSE 2 or NEHAP 2) for the period from 2009 to 2013 under the heading of 'emerging risks' and, to a lesser extent of 'water pollutants'. The Agency is a member of the steering committee of the PNRM, responsible for drawing up and monitoring implementation of the plan. It is also represented in the committee's scientific support group.

Since 2006, the Agency has been working on this topic. In 2008 it developed a ranking strategy for the purpose of determining the most relevant human and veterinary drugs to be screened for in water intended for human consumption. It then developed methods for analysing these substances.In 2011 the Nancy Laboratory for Hydrology published the results of a specific national campaign to screen for human and veterinary drug residues in resources used for producing drinking water and in treated water.

The Agency, in collaboration with the French Health Products Safety Agency (ANSM) is currently defining a general method for assessing health risks related to the presence of these drug residues in water intended for human consumption. A first section dealing specifically with the exposure of humans was published in June 2010. Initially this method will be applied to a human drug and a veterinary drug