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A review of lead in drinking water and its impact on health

A review of lead in drinking water and its impact on health. Meteau. International Conference, 30 th October 2008, Lisbon Dr Colin Hayes 1 & Nina Skubala Swansea University, UK 1 Chair, COST Action 637. Scope of this review. How standards have changed

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A review of lead in drinking water and its impact on health

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  1. A review of lead in drinking water and its impact on health Meteau International Conference, 30th October 2008, Lisbon Dr Colin Hayes1 & Nina Skubala Swansea University, UK 1Chair, COST Action 637

  2. Scope of this review • How standards have changed • The evidence for health impacts from lead in drinking water • The extent to which lead can dissolve in drinking water when lead pipes are present • The numbers of lead pipes that we may be dealing with • The possible extent of risk • Additional problems from fittings • Proposals for a Europe-wide survey [Nina Skubala will present her findings on sampling methods and compliance]

  3. Standards for lead in drinking water • 1970 WHO 300 μg/l “not to be regularly exceeded” Uncommon to sample routinely • 1980(5) EU 50 μg/l (MAC) in “running water” Uncommon to sample at consumers’ taps • 1998(03) EU 25 μg/l (MAC) at consumers’ taps Sampling methods vary • 1998(13) EU 10 μg/l (MAC) at consumers’ taps Harmonization of sampling methods? [The EU standards have followed WHO guidelines, that have tightened to reflect health concerns]

  4. Health effects of lead from drinking water • Studies in Scotland (UK), Wales (UK), Germany and the US have correlated high lead concentrations in drinking water with an elevated body lead burden • Troesken (2006) concludes that the relationship is curvi-linear such that lower lead concentrations in drinking water have a proportionally greater effect • Troesken cites numerous incidents of lead poisoning from drinking water in the 19th and early 20th centuries and concluded that the scale of the problem had been greater than the Chernobyl and Bhopal disasters

  5. Health effects of lead from drinking water • In Glasgow (UK) the mean blood lead concentration decreased from 11.9 to 3.7 µg/dl after lime and phosphate treatments had been introduced (a 69% reduction) • In Edinburgh (UK), the introduction of lime and phosphate treatments resulted in a 64% reduction in blood lead levels between 1983/5 and 1992/3

  6. Health effects of lead from drinking water • In Glasgow (UK) elevated blood lead levels (arising from drinking water) correlated with: ► child development delays and reduced birth weight ► mental retardation among children ► ischemic heart disease ► renal damage ► gout and hypertension • References are available for these studies (1972-89) and will be posted on the METEAU website

  7. Health effects of lead (more generally) • Lead toxicity has been associated with: ► Interference with haem biosynthesis ► Interference with calcium and vitamin D metabolism ► Dullness, restlessness and irritability ► Poor attention span, loss of memory and headaches ► Muscle tremour and abdominal cramps ► Kidney damage, hallucination and encephalopathy ► Hearing impairment, gonad dysfunction ► Violent behaviour • Infants with a high lead body burden have been found to have a reduced IQ by 1 to 2 points • Historically, lead poisoning has often failed to be diagnosed. • Again, references are available and will be posted on the METEAU website

  8. Lead and abortion • Troesken (2006) makes numerous references to the historic use of lead “plaster” tablets to induce abortion • The reported daily recommended dose was 0.004 grains of lead, equivalent to a daily lead intake of 260 µg, or a daily average concentration of 350 µg/l if derived from 0.75 litres of consumed drinking water - but intake via food after cooking in water could reduce this concentration • Highly plumbosolvent drinking water has been shown to be capable of reaching this reported abortion inducing dose - further epidemiological evidence is needed

  9. The extent to which Pb dissolves in drinking water • A standard laboratory based testing technique has been used very extensively in the UK over the last seven years • It is reproducible (if water quality is the same) and has enabled phosphate dose responses and other factors to be determined quickly at low cost

  10. LABORATORY PIPE TEST 30 MINS 25oC NEW LEAD PIPE 50L SAMPLE + TREATMENT CHEMICALS PUMP SAMPLE COLLECTION

  11. LEAD PICK-UP IN PIPE TESTS AT 25OC 140 Median taken from this period 120 100 PLUMBOSOLVENT 80 LEAD ug/l LOW PLUMBOSOLVENCY 60 PHOSPHATED 40 20 0 0 5 10 15 20 25 DAYS

  12. Summary of plumbosolvency test results at 25oC for samples without corrosion inhibitor # # results x 0.5 equate to average ambient water temperature in UK This means that ALL treated drinking waters are sufficiently plumbosolvent to exceed both 10 and 25 µg/l if lead pipes are present

  13. How many lead pipes?

  14. How many people could be at risk? • The KIWA data suggests that around 25% of houses in Europe have a lead pipe (there is much uncertainty). If true, 120 million people are at risk in the EU • In Wales, the %Pb in 39 water supply areas ranged from 8 to 65%, with an average of 28%, based on analytical detection over several years (>11,000 RDT results) • Pb in UK East 22 to 52% by survey; Pb in UK West 59% by survey • The issue is obviously relevant to implementation of the Protocol on Water and Health, and to the development of Drinking Water Safety Plans

  15. Houses with lead pipes and non-compliance with the EU standard of 10 µg/l • KIWA (1998) involving France, Germany, Netherlands, Portugal and UK: 289 houses across 11 areas ► the average weekly lead concentration exceeded 10 µg/l at 64% of the houses that had a lead pipe (note: 69% of the 289 houses had a lead pipe and 44% of the 289 exceeded the standard) • In Wales, 67% of houses estimated to have a lead pipe exceeded 10 µg/l based on RDT sampling (note: RDT exceedance 18.7% and %PB = 28%)

  16. What about fittings? • Recent work on brass manifolds:

  17. UK testing procedures? European Acceptance Scheme – where do we go now?

  18. Proposals for a tap water survey • Proposals circulated following meeting with WHO (June 2008) - 2 year study in each country - risk assessment to identify study areas - area surveys leading to health impact assessment - epidemiological assessment - cost about € 500k per participating country - minimum 6 countries, others can join later • A project planning meeting will be convened in early 2009 to develop the proposal further

  19. Project organisation

  20. Conclusions • Troesken’s account reveals the large scale of historic lead poisoning from drinking water, explained by diagnostic difficulties, ignorance of plumbosolvency and municipal dogma • Prior to lime and phosphate treatments health impacts from lead in drinking water were determined in 2 Cities in Scotland by epidemiological studies • Unless corrosion inhibitors are dosed (and correctly) it is entirely possible that health impacts are being experienced in areas in which the houses have lead pipes, ie: many of the old Cities and Towns of Europe • The proposed tap water and health study must be undertaken

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