Blood Lead Levels in the UK
Lead, the most dangerous thing in Led Zeppelin’s name…
The British satirist Jon Oliver started an HBO piece on lead poisoning with “Lead, the most dangerous thing in Led Zeppelin’s name and, may I remind you, the other thing is zeppelin”. Led Zeppelin had an early hit with ‘Whole Lotta Love’. Perhaps it should have been ‘Whole Lotta Lead’. In the UK there is lots of it, everywhere. What we do not seem to clear about is what impact this is having on blood lead levels.
There appears to be no recent, population wide data on blood lead levels in the UK. This section describes what seems to be all we know.
In 2013 Public Health England decided that there was no need to screen children for elevated blood lead levels. The reasons given were:
- The number of people affected by lead poisoning has been declining for many years. Very few children are now affected by it in the UK.
- The current test is not reliable enough.
- There is a lack of proven treatments for lead poisoning, especially for children only slightly affected and these may even be harmful in these children.
[Ref: The UK NSC recommendation on Lead poisoning screening in children, December 2013, https://legacyscreening.phe.org.uk/leadpoisoning]
Artist: Elizabeth O'Brien, Malveek Dhaliwal.
Artist: Elizabeth O'Brien, Malveek Dhaliwal.
2017 Volcano Art Prize (VAP) Entry.
Title of Image: Making the World Lead-Safe is like doing Jigsaw Puzzles
Lead-Safety Message: Lead ages the brain so doing Impossibles, Mindbogglers, etc Puzzles or other brain activities helps overcome the negative impacts of lead stores coming out of your bones - piece by piece.
This decision is up for review this year and we hope to be included in the consultation. Our counter arguments to the points above are strong and simple:
- There does not seem to be any data to support the ‘very few’ affected conclusion. The data we do have suggests otherwise, but is rather limited and old – see below.
- The tests used in the USA seem reliable enough.
- Removing the source of lead exposure is not going to be harmful and should help.
There seems to be little data about population wide blood lead levels in the UK. There are a few analyses since published the millennium which suggests how bad the problem really could have been.
30 Month Olds
The Avon Longitudinal Study of Parents and Children, University of Bristol, studies environmental and genetic factors that affect a person’s health and development. This included measurement of blood lead levels. One paper from this programme is ‘Effects of early childhood lead exposure on academic performance and behaviour of school age children’ [Ref 1] where the authors state “These data suggest that the threshold for clinical concern should be reduced to 5 μg/dl.“
The full paper has not been accessed, but the BBC reported in 2009 [Ref 2] that ‘The Bristol researchers took blood samples from 582 children at the age of 30 months. They found 27% of the children had lead levels above five microgrammes per decilitre.’ The USA Centre for Disease Control defines elevated blood lead level as over 5µg/dl [Ref 3].
Exactly when these measurements were taken is not clear, however, the whole programme is called ‘Children of the 90s’ or ‘Avon Longitudinal Study of Parents and Children (ALSPAC)’ so is probably analysing data collected around 1993/4, i.e. 30 months after the initial cohort of pregnant mothers was recruited in 1991/2.
[Ref 1: Effects of early childhood lead exposure on academic performance and behaviour of school age children; K Chandramouli, C D Steer, M Ellis, A M Emond; Archives of Disease in Childhood 2009;94:844-848; http://adc.bmj.com/content/94/11/844]
[Ref 2: 'Safe' lead levels harm children; BBC News Channel; 16 September 2009; http://news.bbc.co.uk/1/hi/health/8259639.stm]
[Ref 3: Standard Surveillance Definitions and Classifications; Centers for Disease Control and Prevention; Updated November 18, 2016; https://www.cdc.gov/nceh/lead/data/definitions.htm].
The issue of DIY renovations and risks in pregnancy was described in a 2013 article in the Daily Telegraph [Ref 1] – a major UK newspaper. This referenced the ‘Children of the 90s’ programme. Part of this programme measured blood lead levels in pregnant women and found that 14% had levels greater than 5µg/dl [Ref 2]. However, it seems that this was in 1991-92 when some leaded petrol was still in use, although declining, as shown in the National Atmospheric Emissions Inventory [Ref 3].
The authors do attribute some relationship to renovation work, but do not assess the relative exposure to lead from all sources - “We identified higher educational attainment as an unexpected independent predictor of BLL in our cohort of pregnant women. This may be reflected from exposure to lead during renovation work in older properties.”
[Ref 1: Doing DIY in period homes can put pregnant women at risk; The Telegraph; Claire Carter; 06 Sep 2013; http://www.telegraph.co.uk/news/health/news/10290465/Doing-DIY-in-period-homes-can-put-pregnant-women-at-risk.html]
[Ref 2: Environmental Factors Predicting Blood Lead Levels in Pregnant Women in the UK: The ALSPAC Study; Caroline M. Taylor , Jean Golding, Joseph Hibbeln, Alan M. Emond; 2013; http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0072371]
[Ref 3: Emission summary data for Lead; National Atmospheric Emissions Inventory, 2014; http://naei.defra.gov.uk/overview/pollutants?view=summary-data&pollutant_id=17]
Children With Global Developmental Delay And Learning Difficulties
A small study in Yorkshire of children with global developmental delay and learning difficulties found that 9 out of 104 children had BLL above 5µg/dL. However, this was a selected, small cohort and may not reflect the general population.
The authors made the following comment “We suggest inclusion of BLL as a standard investigation for global developmental delay and learning difficulty, acting as a targeted screening tool, and to start environmental investigations as per HPA protocol at a lower BLL of 0.24 μmol/l (5µg/dL).”
[Ref: Prevalence of high lead levels in children with glbal developmental delay and moderate to severe learning difficulty in Leeds and Wakefield; PD Ghosh, S Sivaramakrishnan, A Seal; Archives of Disease in Childhood 2014;99:A133-A134; http://adc.bmj.com/content/99/Suppl_1/A133.3.info]
That seems to be all we know about the distribution of BLLs in the UK as noted by Dabrera et al in 2015 [Ref 1] – ‘The most recently published evidence for childhood lead poisoning in the UK comes from the Avon Longitudinal Study of Parents and Children (ALSPAC) study in the South West of England in 1995’
[Ref 1: Investigating lead poisoning in children—could surveillance help?; G. Dabrera B. Sampson R. Ruggles G. Leonardi; 2015; QJM (2015) 108 (11): 849-852.; https://academic.oup.com/qjmed/article/108/11/849/1903791/Investigating-lead-poisoning-in-children-could]
We would hope that the removal of lead from petrol has a beneficial effect, and BLLs have come down since, but we do not know how much influence that will have had. Furthermore, blood tests are only one measure. We also do not seem to have any data on bone lead levels.