What are the potential sources of lead in drinking water?
High levels of lead in drinking water can be caused by a range of sources:
- The property has lead pipes
- The property has taps or fittings made of brass which contain lead
- The property has copper pipes with lead based solder
Usually lead enters drinking water because of the corrosion, a reaction between the water and the lead pipe or solder. A low pH and a low mineral content in water are common causes for corrosion. Water is considered to be hard if it has a high mineral content such as salts containing calcium and magnesium.
In Ireland, lead pipes are most common in homes built before the 1970’s, they were often used to join a property to the public water supply. Even when the use of lead pipes was stopped, sometimes, lead based solder was used to join copper pipes in order to save money. It has been suggested, that even brass faucets and fitting which are apparently ‘lead-free’ may leach lead.
Lead levels can decrease as a building ages, because mineral deposits can form a coating on the inside of the pipes if the water is not corrosive, this usually takes about 5 years. Overall, lead levels may be highest in older houses because of the use of lead pipes, but can also occur in newer properties because of a lack of mineral deposits within pipes.
Why is lead potentially dangerous?
Lead can be found in air, food, soil and water. Once lead has entered the human body it is accumulated there; and only very slowly removed. High levels of lead can cause serious damage to the brain, kidney, nervous system and red blood cells. The greatest risk, even at short-term exposure, exists for:
- Young children
- Pregnant women
Lead is a toxic metal known to be harmful if inhaled or ingested. A potential lead exposure can come from different sources, including soil and dust, food (from contaminated containers or air), ambient air and water (mostly caused by the aforementioned corrosion of plumbing). The degree of harm depends on the level of exposure from all sources.
How do I know if my drinking water contains lead?
You should test your water for lead, especially when you see lead pipes or signs of corrosion. Lead pipes are of dull grey colour, which are soft enough so that they can easily be scratched with a key. Signs of corrosion are rusty coloured water, frequent leaks, stained dishes or laundry. If your home was built before 1970 the risk that it may have lead pipes is higher.
When testing water for lead, make sure to use water that has been sitting in the pipe for a while (like the first water flow in the morning) as lead dissolves slowly in water.
What immediate steps can I take to reduce lead exposure?
1) Lead in drinking water:
- Don’t consume water which has been sitting in the pipe for more than 6 hours, ie. overnight. Let the water run until it becomes as cold as it can get, one washing up bowl is usually enough. This should be done for every tap – a shower will not flush your kitchen tap. Flushing is important because the longer water is exposed to lead pipes or solder, the more lead it is likely to contain.
- Don’t consume water from the hot tap because hot water dissolves more lead more quickly than cold water. Always use cold water to make baby formula.
- If you can, ie. have a private water supply, treat water to make it less corrosive, this should generally save money as it reduces damage to plumbing.
- There are a number of different filtering devices available on the market, their effectiveness can vary so make sure that you research your chosen product.
- In the long-term, it is recommended to replace any lead pipes.
2) Lead in other sources:
- Make sure children wash their hands after playing outside.
- Only remove paint if you are sure it contains no lead, otherwise contact an expert to do so.
- Don’t store food in open cans.
Only opinions based upon personal experience or information detailed in academic journals or other publications is cited. This has been done exclusively for anyone who is interested in this subject but is not intended to replace proper analysis. WE DO NOT OFFER MEDICAL ADVICE or prescribe any treatments. This refers to any form of conversation between safewater.ie and our customers, readers or website visitors. We cannot accept responsibility and liability of any kind which may result from the application of this information. We always recommend to consult an expert to discuss any test results or get a full recommendation on the specific subject and specific to your situation by an expert.
There are strict standards for the quality of drinking water within Europe mainly laid down in the EU Drinking Water Directive (98/83/EC). These are based on advice from the World Health Organisation (WHO).