Lead in drinking water
Is Lead Harmful?
Lead used to be common in the environment due to its widespread historic use in petrol, paint and water pipes, as well as its natural occurrence in soils as a consequence of local geological conditions. From the 1970s onwards these uses of lead have been prohibited across Europe and the human health risks have studied extensively and are generally well understood. The health risks relate to the way lead can build up in the body. Those at particular risk are infants and children because lead can have an adverse impact on mental development. Lead may also be factor in behavioural problems. Worldwide it is recommended that human exposure to lead is kept to a minimum and lead is therefore controlled in air, soil, food and water. A full report on the internationally agreed health based knowledge about lead can be found on the World Health Organisation website.
How Does Lead Get Into Drinking Water?
Occasional lead occurs naturally in groundwater however, this is a rare situation in the UK and lead is not present in the water within our wider public water supply network. However before 1970, many smaller water pipes were made from lead. Although lead pipes have not been permitted for this purpose for four decades, in older properties it remains possible that part, or all, of the underground service pipe connecting the water main in the street to your kitchen tap may be made from lead. It is also possible that some original lead plumbing remains within older properties especially if the kitchen has not been modernised. In hard water areas the scale that forms on the inside of pipes protects against the dissolution of lead from the pipe into the water. However in soft upland water supply areas there is a greater likelihood of lead from pipes being present in the water. Where this risk exists, water companies treat the water with orthophosphate and this reduces the problem significantly. None the less, particles of lead may build up in these older pipes and intermittently appear in tap water.