A new scientific paper on the human health impacts of lead ingestion from gamebirds shot with lead has recently been published.
This study uses measured levels of lead in gamebirds on sale in the UK to estimate health impacts.
Perhaps the most striking proposed impact is that for children, eating lead-shot gamebirds around once a fortnight would lead to a whole point reduction in IQ.
As an adult, if you eat game at a frequency of somewhere between every day and every week then you noticeably increase your systolic blood pressure, risk of chronic kidney disease and, in pregnant women, the risk of spontaneous abortion.
Now, I don’t eat game anything like that often, and maybe you don’t either, but it is highly likely that some people do – eg gamekeepers’ families. BASC is sitting on data on game intake which they have so far refused to disclose publicly despite being asked to reveal these data at the Defra/FSA Lead Ammunition group (see cryptic minutes here, here, here). It is thought that these data would disclose some surprisingly high intakes of game meat for some sectors of the game-shooting community.
Given that the details of the health impacts of lead in game food have been produced by nature conservationists as spin-offs from studies of non-compliance with existing legislation on ammunition use by hunters, and the conservation impacts of lead on wildlife, it is time for the shooting community to step forward and do the following:
- BASC should publish their questionnaire survey data on game meat intake – if intake levels are uniformly low then this is a non-issue in human health terms. BASC’s long term refusal to disclose the information is obstructive. If these data show (or suggest) high game meat intakes for some people then the refusal to disclose this, and refusal to call for a move to non-toxic shot, are both scandalous.
- BASC and the Countryside Alliance should make it clear whether they have any concerns about the paper referred to here. Do they accept the science, and if not, why not?
- If BASC and Countryside Alliance accept the science then what implications are there for the sale of game meat shot with lead and their position on non-toxic shot?
The paper briefly described here, though it is publicly available so you can read it yourself, is just the latest small advance in our knowledge of the impacts of lead on animal and human health. It is an elaboration of previous knowledge rather than a shocking revelation. The general impacts of lead on wildlife and human health have been known for years – and known to the shooting community for years. And yet the shooting community has taken no action at all to clean up their act. This is a badly-led community, stuck in a rut and closed to any new ideas or evidence.
If the shooting community had had the faintest glimmerings of common sense then years ago they would have promoted the use of non-toxic ammunition and claimed the moral high(-ish) ground. Instead they have promoted the eating of game, knowing of the health impacts of lead ingestion, and vilified those who seek simply for shooting to use non-toxic ammunition. As time goes on the shooting community digs itself into a deeper and deeper hole on this issue ‘led’ by the Countryside Alliance.
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Wow, do people really eat game that often, I suspect not. A bit of a storm in a tea cup I think.
Connormead – I strongly suspect that you are wrong – to the extent that some people eat a lot of game, and in any case this study shows that it doesn’t have to be very high levels of intake to have a health impact. But let’s hear from BASC who asked their members how much game they ate. If BASC know, or suspect, that game intake levels amongst their membership are very low then they should say so. If they know or suspect that they are high, then they should say so. They are being obstructive and secretive about the results of their survey.
“As time goes on the shooting community digs itself into a deeper and deeper hole on this issue ‘led’ by the Countryside Alliance”.
I completely agree, it is high time that CA supporters paused to reflect on the failings of the CA and in particular the tenous, lightweight economic arguments that they use and the seemingly instinctive inclination to turn all issues surrounding the British countryside into a purile town versus country debate.
I was against the hunting ban, not that I hunt with myself, however every time a charmless and rather angry spokesman for the CA popped up in the media and lectured the nation on how the rural economy would disintegrate if hunting was banned and the less pro-hunting I felt. I know many other people felt the same. The debate surrounding the hunting ban should have centred more on liberty and less on livelyhoods.
As a keen angler I also wonder what the CA has for the good of angling and the wider freshwater environment, very little it appears. Instead it seems more intent on going to war with canoeists and cormorants. I suspect it won’t be long before the Otter is the CA’s next target.
With regard to the reluctance to switch to non-toxic forms of ammunition, no doubt we will hear the same weak economic arguments from the CA.
I followed the link and have not purchased the article have you or anyone else out there? What are “game birds” the only graph on the link is for duck and seabirds that possibly have ingested shot and have lead in their systems.
I doubt if reared pheasant and partridge have this problem so as the researchers remove the shot from the birds after cooking are they looking at duck or are they showing that lead leaches out of the shot during the cooking process and pollutes the meat of pheasants. Or have they lumped them together.
Andrew – here is the link to the original paper (which is completely and freely available online) on lead levels in purchased game food in the UK http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0010315
It includes red grouse, pheasant and partridge. It is well worth a careful read. You couldn’t sell much of this meat with these lead levels if it were pork, chicken, beef, lamb etc.
Lead is a problem for wildlife through ingestion. Lead is a problem for humans with high game intake through fragmentation of lead ammunition through the carcass.
Thank you for your comment
I am reminded of Mark Thomas on Channel 4 who, standing outside a London Arms Dealers Fair, said to the police “There’s a bomb in there”, they looked very reluctant to react! If the lead concentrations are dangerous, surely it only takes one specific complaint about high lead levels in game sold as food for the authorities to be forced to respond? If the suppliers of game are reluctant to act who are food/health authoritiesand regulators responsible?
Peter – there are no lead levels set for game meat – I wonder why? If beef, lamb, chicken or pork were sold with lead levels of game on sale much of that meat would have to be withdrawn from sale. You are right that the FSA should be doing something – I wonder whether they will? But as long as BASC refuses to disclose their data on game consumption we won’t know as much as is useful and important to get a better picture.
I remember the Glen Fesshie deer cull incident…when the gamekeepers were outraged at helicopters being used to extract the deer in bulk and formed a spontaneous demonstration. One of them mentioned it was not clean to the press and the BBC brought in Proff Pennington to give an expert view on hygene. They were only a hairs breadth away from having the entire game market shut down! The landowners were furious and there was blood on the carpet.
Hugh Pennington was clearly shocked and bemused that game, shot and cleaned with rusty knives in the field……dragged through the heather (or carried in a dogs mouth)… piled into the back of a dirty landrover etc…could possibly end up in the human food chain.
Long term ingestion of lead impacting in intelligence and rational thought? We should have this investigated by the House of Lords…………if they are still capable?
Circus – it’s so easy to mock but…no, go on!
Just a couple of days ago, the Aberdeen Press and Journal (and presumably many other local and regional newspapers) carried a letter from BASC promoting the health benefits of eating game meat, in anticipation of the start of the pheasant season on Monday.
The essence of this I am sure is correct to a point. I am sure that the reality of the situation is that plenty of people eat game fairly regularly, is their health being impacted much, I am not sure.
Is there a problem with lead ammunition use going forward? Possibly. Is the real issue the lead in the wider environment? Probably. Surely rather than debating the problem to human health we should worry about the (main) environmental issue.
Last issue…… Mark, you are seen as a sensible pillar of thie conservation furniture. You are not perceived as anti shooting per se, surely some of your recent comments about shooters and shooting organisations are divisive not conciliatory. I agree with you and your readers about failings in the CA (possibly them backing lead will only hasten its demise!) I do think that you would share lots of common ground with BASC which aligns itself with science rather than ideology. Most shooters are a passionate about the environment as you are and have more in common with you than you might think!
Thanks for the link and I read the whole report. I think your pushing the limits on this one as the report stated that an individual who might eat 2.2 meals a week for 52 weeks a year might exceed the recommended limit. For the vast majority of people who eat game this is a very unlikely scenario unless they had a very big freezer and a very limited palette ! Julian
Julian – thank you for your comment which clearly shows that you have read the paper. I have to say that that is a rarity as most shooters who comment on this topic clearly haven’t! I agree that, as I understand it, it is only going to be people with lead levels well above average that face any serious health impacts. I still eat some game, and enjoy it. However, things have moved on since the paper you read so here is another one to read! This paper from the European Food Safety Authority removed the PTWI (Provisional Tolerable Weekly Intake) on which your comment is based, on the basis that ‘there is no evidence for a threshold for critical lead-induced effects. In adults, children and infants the margins of exposures were such that the possibility of an effect from lead in some consumers, particularly in children from 1-7 years of age, cannot be excluded. Protection of children against the potential risk of neurodevelopmental effects would be protective for all other adverse effects of lead, in all populations.’. Here is the link http://www.efsa.europa.eu/en/efsajournal/pub/1570.htm
And, that level is for the population as a whole. We know that children and fetuses (and therefore pregnant women) are more vulnerable and therefore their intake should be even lower.
What is needed, as in yesterday’s blog, is information on game intake rates to assess risks. You say, that 2.2 meals of game a week is an unlikely scenario but it is a common scenario among certain groups on the continent of Europe and, in private, people in the hunting community say that it is a perfectly reasonable level of intake for quite a lot of people. And, as per this reply to you, we are no longer justified in using a level as high as 2.2 meals a week.
BASC carried out a survey of its members several years ago to assess game intake. This was at a time when the ‘Game to Eat’ campaign was in its early days (it continues still). BSC refuses to make the results of that survey available and there are rumours that they would show that game intake levels are higher than you or I would imagine. Why are they being kept secret?
“anticipation of the start of the pheasant season on Monday.”
There must be a different calendar operating in Wiltshire – the Goons have been blasting away since Thursday.
“rather than debating the problem to human health we should worry about the (main) environmental issue.”
Yes, but, No, but – meaningful action is more likely when human health is impacted.
“Perhaps the most striking proposed impact is that for children, eating lead-shot gamebirds around once a fortnight would lead to a whole point reduction in IQ.”
This is scare-mongering and bad science on an embarrassing scale, and is impossible to endorse with the results of this small study.
You ask for weaknesses in the science behind it, I’ll give you a few points to consider.
Anything less than half a pellet in size was homogenised, which is highly unlikely to accurately replicate the process of digestive system on a lead pellet. For a start it greatly would increase the surface area of the lead available for reaction in the body, and secondly assumes that anything less than half a pellet in size is always ingested. There is no evidence to support that this a correct methodology.
In addition to this, the number of birds obtained for the sample was extremely small, and very unlikely to be a robust source of evidence that can be relied upon. I would not be confident on basing assumptions on the entire game consumption in the UK from 9 partridge (the data from one was discarded), just 7 duck (three mallard excluded from the study). Although it doesn’t specify how many woodcock and pheasant were excluded from the sample, it talks about the total of 32 birds, so we can assume that there were 16 in total, which might mean it would be reasonable to suggest, that there were perhaps just 8 of each.
The report continually relies on percentages, which it seeks to attempt to hide the fact that when they talk of percentages they may be looking at a sample size in the case of mallard of just 7 birds.
This is at best a basic pilot study, and to base and extrapolate elaborate conclusions on the safety of consuming gamebirds is not only irresponsible but poor scientific practise.
Will – welcome to this blog. you don’t make several points, you make two points. One is that he sample size is small – not that small but the results are just as likely to be worse as better if the samples are small. As I understand it, the meat was homogenised which doesn’t mean that the pellet fragments were. But thank you for a good attempt.
Thank you for the welcome. You seem to concede the point about homogenisation and so I relate you to the specific paragraph that relates to the homogenisation for your reference, it reads clearly to me that the lead is homogenised within the meat:
“Once cooked, any apparently whole gunshot or large fragments of gunshot that could have been detected by the consumer (i.e. ≥half a shotgun pellet), were removed by dissection and stored, and the cooked meat was separated from the skeleton. Meat and sauce samples were homogenised separately using a hand blender, weighed and oven dried at 20°C to constant weight.”
I think you will find that I made more than two points, one of these points which you overlooked is the fact that this is at best a small pilot study and completely unsuitable and irresponsible to base elaborate conclusions as you attempt to, in the sentence I quoted and took issue with. This is bad science. You should consider reading the book by the same name by Dr Ben Goldacre as it may help add some perspective. It’s not a long read, and I suspect you will enjoy it.
Regarding the assertion you make regarding the sample size being “not that small”, it is small – ridiculously small. You seem to think that the sample size is irrelevant but it completely undermines any findings of this study.
The assertion that: “the sample size is small – not that small but the results are just as likely to be worse as better if the samples are small.” Is factually incorrect. What we are talking about is statistical anomalies, regardless of whether someone would prefer to have one outcome or another, as the sample size decreases then the likelihood of statistical error increase dramatically. We are not talking about averages being equally likely to be better or worse, but instead on the fallacy that as little as 7 birds in the case of the mallard is an accurate representation to attempt to draw statistically significant results. It’s like flipping a coin 5 times, and getting heads all 5 times, fairly unlikely and with a p <0.05 a statistically significant result, and I am sure ripe for some obscene extrapolation. But does this mean the coin was biased, or was it just purely by chance?
Science and statistically significant results are all about explanation of results by known variables, in this case lead shot. But with such a small sample size and so few data-points it is just not a robust study.
Never-the-less I do appreciate your response, and approval of my comment. I am friends with a relative of yours and he has always spoken highly of you.
Will – as you see, the statement that you quoted says that the meat is homogenised. The meat contains the tiny lead fragments. The meat has to be homogenised to be analysed. That doesn’t mean that the lead is further broken up by this process. You make an interesting point but my interpretation would be that it isn’t a particularly telling one. Although if you know the relative that I guess you might then you might have some experience of meat analysis – am I right?
Your second point, and I think there were only two, was that the sample size is small. Across the whole range of different types of meat the sample size was high – this wasn’t a study of just mallards was it? All the samples of the different types of meat (I don’t have the paper to hand to check, but from memory that was pheasant, partridge, grouse, wood pigeon, mallard, deer and rabbit at least – weren’t there snipe and woodcock too?) gave similar results. The fact that there were many types of meat analysed is important as it pertains to my correct assertion that ‘the results are just as likely to be worse as better if the samples are small’. If the results for mallard were the results of statistical error, as they might be perhaps, then they are just as likely to underestimate the problem as overestimate it. A small sample gives an unbiased estimate of the mean whose accuracy increases with sample size. And the point is, that if the results were very prone to statistical sampling error then they should differ across the many meats sampled (venison, rabbit, pheasant etc). Since they do not – all show pretty high lead levels – far higher (on average) than would be allowed in non-game meat on sale – then your point about the sample size is, of course, worth considering but doesn’t appear very strong to me.
But thanks for making these two points.
The first paper reported here appears to be a meta-analysis of existing data, which is a recognised method for creating more questions than answers, usually to justify the funding of further research. Is it really a scare-story, or an erudite statement of the blindingly obvious? What credence should we give to a potential reduction of IQ by one point? Is it possible to measure a difference of one point of IQ between individuals? Would reading tea-leaves be more useful? Does the loss of one point of IQ matter more to someone with a low IQ than to a genius? Are there differences between brands of ammunition? Does a high-fibre diet help to sequester soluble lead?
Lead is poisonous. Game species shot with lead contain lead. The more lead there is in the game-meat, the more poisonous it is. If you eat more game, you accumulate more poison. It’s not rocket-science.
Evidence-led policy is reliant on the support of this type of research to underpin decisions taken by the Administration, who are congenitally blind to the obvious when there is a potential effect at the ballot box. Once something becomes uncomfortably obvious, even to the Administration, there will be a new call for policy-led evidence-seeking. And so it goes on, for ever, paid for by everyone.
Where is there a Major _ de Coverley when we need one?