Hemp Bioaccumulation: The Good and the Bad

What is a bioaccumulator?

In the broadest sense, bioaccumulation is the process by which an organism absorbs material from its surroundings more efficiently than it can be eliminated. Essentially, a bioaccumulator is particularly effective at intaking chemicals, good or bad, but is also unable to expel those chemicals as waste.

Although they may not be explicitly categorized as such, bioaccumulators are popularly represented in media relating to environmental and climate issues.

For example, spilled oil and microplastics accumulate across the members of ocean ecosystems, pesticides and heavy metals accumulate in crops grown in heavily treated or contaminated soil, and humans exposed to even trace amounts of radioactive material can suffer long-term health issues because the body is not equipped to eliminate such substances.

Bioaccumulation is one of the main reasons that leakage of unwanted material into the environment is so intensely problematic: it is the mechanism by which toxic materials are capable of leaching into universally life-critical parts of any ecosystem.

On the other hand, plants that are especially efficient bioaccumulators can be useful to heal environments in which contamination of toxic material has occurred. “Nitrogen-fixing” plants, for example, extract nitrogen from the air to aid in fertilization, resulting in higher concentrations of nitrogen in the surrounding soil.

Also referred to as bioremediation, nitrogen fixation is one of many bioaccumulative processes that are sometimes used to naturally re-fertilize soil that has been depleted of nutrients or contaminated with toxins.

For better or for worse, some examples of natural bioaccumulators are:

  •   Alfalfa
  •   Peas
  •   Canadian goldenrod
  •   Red algae

And, our favorite:

  • Hemp!

Hemp: The Renaissance Plant

In the early 1990s, Dr. Ilya Raskin of Rutgers University began an experiment planting bioaccumulators and bioremediators in the area around the Chernobyl nuclear power plant in then-Ukrainian Soviet Socialist Republic.

While some plants were found to specifically not absorb dangerous radionuclides from the soil, other experimental crops–like hemp– were found to rapidly and effectively clean waste from the soil.

While much of the damage to the Chernobyl exclusion zone is irreparable, the findings of Raskin’s experiments with hemp prompted lasting, global efforts to utilize hemp’s capability for bioremediation to promote environmentally conscious farming techniques.

Fiber from hemp plants is also considered an ideal candidate for sustainable, carbon-negative building material. A 2002 study from the University of Toronto found that a natural fiber composite made of industrial hemp for insulation was as efficient or more efficient than commercially available fiberglass alternatives, and that the hemp fiber composite insulation would sequester an estimated 325 kg carbon per metric ton of hemp over the course of the material’s useful lifespan.

Similar research has suggested that building with hemp-based concrete could significantly reduce carbon emissions of entire communities.

But today, the use of industrial hemp crops in the United States is still focused largely on processing of flower material to produce consumable hemp products, like CBD oils. For this purpose, hemp’s bioaccumulation superpower becomes a potential hazard.

Where do pesticides go after they are sprayed on growing hemp crops? What about heavy metals that could be present in the soil? The hemp plant reliably absorbs pesticides and heavy metals from its surroundings, and as described by the principle of bioaccumulation, is not capable of efficiently eliminating them.

The Problem with Bioaccumulation

In the years since hemp farming and processing has become legal and popular, an absence of regulatory oversight has left blind spots for safety in the industry.

While use of pesticides in farming may be common practice, hemp does not currently fall into the same legal category as edible crops for the purpose of safety standards relating to pesticide type and concentration of use – thus, no enforceable limit exists on the use of agrochemicals that could potentially be absorbed by the hemp plant at a high rate and remain present throughout processing.

Is bioaccumulation just a hemp farmer’s problem, then? On the contrary – although a hemp processor’s main goal is to concentrate and extract cannabinoids from raw material, the methods of concentration and extraction do not solely target the desired chemicals.

Other chemicals present in the hemp such as pesticides or heavy metals are often concentrated and amplified alongside the desired cannabinoids and terpenes being extracted and isolated.

Therefore, the problem of bioaccumulation follows the supply chain all the way through the formulator and manufacturer at risk of using contaminated excipients to produce a hemp-derived cannabinoid product and on to the retailer stocking shelves with those products.

Ultimately, hemp bioaccumulation puts consumers at risk when products are not properly and thoroughly tested for such contaminants.

Unfortunately, the lack of compliance standards for pesticides and heavy metals yielded reports of hemp-derived CBD products that were found to be contaminated with unsafe amounts of lead, copper, nickel, and various agrochemicals.

Even worse, some contaminated products came with hemp testing laboratory results stating mistakenly – or fraudulently – that the product contained no unsafe levels of contaminants.

Unvalidated methods, improper preparation, and a lack of training in hemp testing laboratories could certainly result in mistakenly reporting acceptable levels of pesticides and heavy metals.

State by state, compliance standards for safety in industrial hemp farming and processing are slowly being developed. These developments have caused some confusion for farmers, rightfully so, since each state potentially has different requirements for compliance testing.

Whether hemp’s incredible ability to accumulate material from its environment is a blessing or a curse, testing for heavy metals and pesticides in raw hemp material is imperative.

Compliance Testing for Hemp with Santé Laboratories

At Santé Laboratories, we help you define compliance specific for your product. We have responsibly developed and validated multiple, best-in-class analytical procedures to support hemp and CBD products for compliance and peace of mind. Using industry-standard ICP-MS, we screen for Class I and Class 2A elemental impurities.

Class 2B and Class 3 can also be tested upon request. These include lead, arsenic, cadmium, mercury, nickel and more. Using both LC-MS/MS and GC-MS/MS, we can carefully quantify 66 of the most widely used pesticides based on California compliance recommendations, which tend to be the most stringent.

Otherwise, there are other pesticides panels that can be selected based on Texas recommendations or simply common pesticides used in the United States.

Compliance testing is the only way to be sure that your plants, extracts and products do not contain harmful pesticides, heavy metals and more. Ensure that you are utilizing a trusted hemp testing laboratory for all of your testing needs.

For more information about our scientifically validated compliance testing and hemp analytics, visit santelabs.com.


Sources:

https://www.sciencedirect.com/topics/chemistry/bioaccumulation

https://www.nature.com/scitable/knowledge/library/biological-nitrogen-fixation-23570419/

https://www.thespruce.com/nitrogen-fixing-plants-2131092

https://pubmed.ncbi.nlm.nih.gov/26194234/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5852493/

https://www.world-nuclear.org/information-library/safety-and-security/safety-of-plants/chernobyl-accident.aspx

https://www.rollingstone.com/politics/politics-features/can-hemp-clean-up-the-earth-629589/

https://www.nytimes.com/1992/09/08/science/scientists-using-plants-to-clean-up-metals-in-contaminated-soil.html

https://www.researchgate.net/publication/320058537_Assessment_of_Carbon_Sequestration_of_Hemp_Concrete

https://www.sciencedirect.com/science/article/abs/pii/S0921344902001738

https://hempindustrydaily.com/chart-michigan-to-increase-2020-hemp-production-but-53-of-2019-crop-is-still-unsold/

https://www.foodnavigator-usa.com/Article/2020/05/11/Lawsuit-over-heavy-metals-in-CBD-products-raises-more-questions-than-answers-says-attorney-Hemp-Authority-seal-gains-traction

https://hempindustrydaily.com/florida-finds-elevated-lead-levels-in-some-hemp-products-in-stores/

 

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