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Medical Beware of lead...

  1. Jun 17, 2017 #1
    Is lead in the US food supply decreasing our IQ?
    The environmental advocacy group Environmental Defense Fund (EDF) on June 15 released a study about dietary lead exposure, with a focus on food intended for babies and young children.

    isleadintheu.jpg


    Using a Federal Drug Administration (FDA) database of food samples, EDF reported some pretty worrying numbers, most remarkably in fruit juice samples intended for children. For example, 89 percent of the baby food grape juice samples had detectable levels of lead in them.​


    https://medicalxpress.com/news/2017-06-food-decreasing-iq.html#jCp
     
  2. jcsd
  3. Jun 17, 2017 #2
    From the study:

    Overall, 20% of 2,164 baby food samples and 14% of the other 10,064 food samples had detectable levels of lead. At least one sample in 52 of the 57 types of baby food analyzed by FDA had detectable levels of lead in it. Lead was most commonly found in the following baby foods types:

    • Fruit juices: 89% of grape juice samples contained detectable levels of lead, mixed fruit (67%), apple (55%), and pear (45%)
    • Root vegetables: Sweet potatoes (86%) and carrots (43%)
    • Cookies: Arrowroot cookies (64%) and teething biscuits (47%)
    We also found that the baby food versions of apple and grape juice and of carrots had samples with detectable lead more often than the regular versions.

    detectable_lead-600.jpg


    https://www.edf.org/health/lead-foo...942.363465047.1497539228-274183335.1497539228
     
  4. Jun 22, 2017 #3
    And people should know to use cold water to create tea, coffee, soups, and other food products as water from hot water tanks will tend to have higher lead levels!
     
  5. Jun 22, 2017 #4

    Drakkith

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    How much lead is "detectable amounts"?
     
  6. Jun 22, 2017 #5

    jim mcnamara

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    FWIW - lead is found in some farm soils in developed countries. It got there in part from tetraethyl lead additives to gasoline. In the US, leaded gasoline was phased out over time, so lead in some soils has decreased to undetectable levels, and soils in very remote places were not subject to much lead input to start with. Some soils have always had detectable lead levels because of soil material origins. Some had none. Soils and canning processes + machinery are probable sources of most lead.

    @Drakkith - see https://www.fda.gov/food/foodscienceresearch/totaldietstudy/ucm184293.htm and download one of the pdf files. 2006-2013 is a good choice.
    The limit of detection varies somewhat by the method and food stuff: 0.005 mg/kg to - .020 mg/kg, with associated limits of quantification. Trace is defined as above LOD ≤ LOQ. The n Beelzebub mention is the number of trace hits over time. Percentage is the number of trace hits / total tests for given food item.

    This has links discussing limiting exposures to lead. https://www.niehs.nih.gov/health/topics/agents/lead/index.cfm
     
    Last edited: Jun 22, 2017
  7. Jun 22, 2017 #6

    jim mcnamara

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    FWIW some of the science reporting is overdoing it a bit. Yes, lead is bad. But anyone who grew up in suburban/urban areas prior to 1972 was exposed to lead everywhere in minute amounts. See this: Clair Paterson's fight to get lead out of gasoline
    https://en.wikipedia.org/wiki/The_Clean_Room (Cosmos episode)
     
  8. Jun 23, 2017 #7
    jimmcnamara, thanks for all the information and the links! :smile:
     
  9. Jun 23, 2017 #8

    Vanadium 50

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    "Detectable levels" is not a very good standard. If your detection improves, do things get worse? Certainly the statistics get worse. If you're willing to pay the money, I'd imagine we can get to a sensitivity of few atoms per ml.

    The EPA water limit is 15 ppb. 0.005 mg/kg in grape juice is 5 ppb. I make no claims as to the absolute safety of either number - this is simply a comparison between "determined safe by the EPA" and "measurable".
     
  10. Jun 23, 2017 #9
  11. Jun 23, 2017 #10

    jim mcnamara

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    @Vanadium 50 - yes you are correct - I was answering @Drakkith and reported what the document had. You correctly noticed that detectable limits were essentially meaningless. And over time the detection methods have gotten more sensitive. :eek: I cannot tell definitively if that was taken into account in the dataset or not. Look at a file - there is no prescribed lab methodology in the pdf - it may be one of those 'everybody knows' deals, except for me.

    All of this stuff related to nutrition and contamination goes through filtering - for clickbait improvement IMO - by websites after readers. Not necessarily after clear, unbiased reporting. I would guess most of the posters here have all kinds of lead sources in and around the house: batteries, antique wooden furniture, ceramics. Lead is toxic, but industrial societies use it extensively. And history of use impacts our exposure to lead and heavy metals as much if not more than current use. We would all be complete morons if what the edf.org article implied were completely true about lead contamination. That site has a strong political leaning. Not science, IMO.

    Not mention 'getting the lead out' of our modern environment is both desirable and incredibly expensive. We live in a practical compromise.
     
  12. Jun 23, 2017 #11

    jim mcnamara

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    @Beelzebub - the site does not link to anything describing lead limits, except for 0.25% lead in plumbing as being certified 'lead free'. See button #4 and follow the link on lead levels. I'm guessing that is set by detectability limits that Vandium 50 pointed out. So, in the strictest possible sense: lead free is not lead free necessarily. The devil is in the details.
     
  13. Jun 23, 2017 #12
    Thanks a bunch for all the information! I'm not from the US, and I wasn't aware of that site's political leaning.

    It's reassuring to know that it's not as dramatic as they claim it to be. I was aware though of some historical disputes regarding lead - namely its possible role in the demise of the Roman Empire.
     
  14. Jun 23, 2017 #13

    Ygggdrasil

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    An NPR news story on the EDF report noted that:
    However, it also notes:
    The question of what levels of lead should be allowable in baby food certainly has scientific aspects—what are the lead levels detectable in foods, what levels are known to cause health problems—but the question is more of a policy question where other factors must also be taken into account—what nutrients might be harder to obtain if one avoids foods with detectable lead, what would be the costs associated with removing lead, would the potential benefits outweight the costs, would lead prevention resources be better spent on other efforts (e.g. removing lead from pipes and building which are probably more common in areas of lower socioeconomic status, rather than making marginal lead reductions in expensive baby foods that rich people buy).
     
  15. Jun 27, 2017 #14
    For any heavy metal, the human body can compensate for levels of concentrations that will vary person-to-person. Still, there are some levels that can be determined to produce adverse effects in all people, so we try to never exceed those levels. The bioavailability of the metal is also a factor. Lead ingested through the GI tract is far less dangerous than any that might be present inhaled into the lungs, for instance. Most of the lead that passes through the intestinal tract will continue out of the body without reaction. There is no "outlet" from lung tissues so that body will have to either metabolize it or leave it in place. Serum lead components may still be cleared through the kidneys, whereas any heavy metal that reaches an end-organ will be more greatly affective since it becomes stuck in that location, including the brain of growing kids. For adults, we accumulate small amounts of heavy metals throughout our lifetime. However, our tissues are not growing in the same rapid fashion as with children and there lies the difference.
     
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