Monday January 25 2016
Lead is highly poisonous
"Paint on playground equipment has been found to contain high amounts of the toxin lead – up to 40 times recommended levels," BBC News reports.
Researchers sampled levels at 26 playgrounds in the south of England and the results are worrying. Lead is well known to be a highly toxic metal and its use has been phased out over the years. Young children are particularly vulnerable to the effects of lead poisoning, which can affect both physical and mental development. Even small amounts of lead can be harmful.
As well as playgrounds, researchers also tested other public structures (272 in total) such as bridges and "traditional" telephone boxes.
Lead was detected in the majority of all 272 public structures tested, and over a third had lead concentrations exceeding the recommended 5,000 micrograms per gram (mcg/g) limit.
The average level from all samples was around 1,000mcg/g, but some had levels up to around 100,000mcg/g. Also, it wasn't always those in a poor state of repair – some newly painted structures without visible flaking had levels exceeding the limit.
This study doesn't directly demonstrate any harms to children or people in general from touching these structures, but it does highlight an important concern for the public, and those involved in renovation and maintenance.
Encouraging your children to wash their hands after playing with playground facilities should help reduce the risk of any exposure.
Where did the story come from?
The study was carried out by two researchers from the School of Geography, Earth and Environmental Sciences, at Plymouth University.
The study received partial funding from a Marine Institute grant from the university, and was published in the peer-reviewed scientific journal Science of the Total Environment.
The quality of the UK media's reporting of the study was mixed. While the overall findings of the study were reported accurately, many of the figures quoted do not correspond with the study. For example, the BBC says 50 playgrounds were tested, but the study only mentions 26 being tested.
What kind of research was this?
This was a cross sectional study that analysed the lead content in paint on a variety of structures in the urban and suburban environment of Plymouth.
The toxicity of lead is well established, in particular its effect on the development of young children – the reason why the use of lead in products was phased out over several decades. However, previous research has documented that household paint particles contain various leaded pigments, causing paint to come under strict legislation. The US and other countries have set a limit for lead in consumer paints at 90 parts per million (ppm).
However, an environmental source that has received less attention is the paint used on external structures, particularly those where weather conditions lead to flaking paint. This study aimed to use a portable device – an X-ray fluorescence (FP-XRF) spectrometer – that would allow the researchers to analyse the paint content in a variety of structures in Plymouth.
This is a device that can accurately measure the amount and types of chemicals in an object.
What did the research involve?
The researchers visited 15 urban and suburban regions of Plymouth between February and April 2015. All visits were made in dry weather conditions. They examined as many painted public structures and facilities that they could access from roads or pavements, including gates, railings, post and telephone boxes and playground facilities.
They either assessed them with the FP-XRF spectrometer on site, or took samples from those that were visibly flaking for analysis in the laboratory. Overall they took 272 analyses – 58 on-site measurements and 224 paint fragments taken for laboratory analysis.
What were the basic results?
Lead was detected in 81% of all samples taken (221/272), with concentrations ranging from 20 to 389,000mcg/g of paint. The US safety limit of 5,000mcg/g was exceeded in just over a third (38%) of all of the samples analysed.
Telephone boxes and bridges were the environmental structures with the most extensive paint flaking, and these structures had the highest lead concentrations. Their median (average) concentration was around 30-40,000mcg/g, and in 21 samples the lead exceeded 100,000mcg/g.
Looking at playgrounds specifically, 26 samples were analysed, and lead was detected in 20 of them. The average (median) lead concentration was 1,170mcg/g.
Lead was detected in all colours of paints, though levels were generally lower in grey/silver/white surfaces and higher in brown and red surfaces.
Chromium – another toxic metal – was also detected in 106 of the samples.
How did the researchers interpret the results?
The researchers conclude: "Since the issues highlighted in the present study are neither likely to be restricted to this city, nor to the UK, a greater, general awareness and understanding of the sources and routes of exposure of exterior leaded paint is called for."
This research has analysed the lead content of a variety of painted public structures in the urban and suburban environment of Plymouth.
Though the research was not primarily intended to examine playground structures, as the researchers said: "Perhaps the greatest concerns arising from our research are the wide occurrence and high concentrations of lead in paints on public playground facilities."
Their tests included a variety of playground structures, such as roundabouts, climbing frames and monkey bars. Of the 26 samples measured, the average lead level was 1,170mcg/g, which is well below the recommended environmental limit of 5,000mcg/g. However, this average came from some playground samples with low levels (minimum 116mcg/g) and some with very high levels (maximum measured 115,000mcg/g).
The greatest risks are believed to be from older peeling paint on structures that children are in direct contact with, such as rails, swing or slide posts and climbing frames – particularly toddlers who are more likely to touch these surfaces and then put their hands to their mouths. However, as the researchers found, the highest levels don't necessarily always come from the oldest surfaces. One of the samples they took where lead levels exceeded 5,000mcg/g came from a range of facilities with generally intact paint that had been applied quite recently – date marked 2009.
The highest lead levels measured in the study came from bridges and telephone boxes – older structures in a poor state of repair. As the researchers suggest, the higher levels in these old structures may be the result of progressively newer paints containing less lead.
However, the risk from these items wouldn't necessarily just be restricted to people touching these structures. Flakes of lead paint could contaminate soil, surface water and dust on roads and pavements. This could in theory result in lead particles being brought indoors on shoes and clothing.
It is important to note, that while the potential that children or people in general could be at risk from touching painted external surfaces – or from bringing lead particles into the home – are highly plausible, they are not directly proven by this piece of research.
This study is also restricted to Plymouth, though as the researchers rightly say, there is no reason to suspect the findings would be limited to the environment of this city. Overall the findings are an important point of awareness for the public and those involved with the renovation, repair and maintenance of a wide variety of painted external structures. They also highlight the need for close regulation of the lead levels in paint.
The best way to prevent your child being exposed to lead is to encourage them to always wash their hands after outside play and before eating. Regularly washing any of their toys or equipment they play with outside should also help.