Money Doesn’t Grow on Trees, but Nickels Do

     The agriculture industry is now harvesting more than just food. Some plants can harvest metal, such as nickel, through a phenomenon known as phytomining. In a recent article from The New York Times, Ian Morse examines this agricultural phenomenon. The sap of these phytomining plants can be sliced open or put through a peanut press to harvest the one-quarter nickel sap. This nickel-producing sap is more concentrated than the 1.2% nickel ore produced from smelting.

     Plants phytomine by collecting minerals from the soil and storing them at high levels, known as hyperaccumulation. There are approximately 700 known plants that thrive in metal-rich soil, at least 65 of which can phytomine nickel. These plants have adapted to their metal-rich environments and they are thought to use the nickel to control pests or more easily gather potassium from the soil.

Fig 1: Testing paper turning a reddish color, indicating high nickel content.

     Dr. Alan Baker from the University of Melbourne has researched the relationship between plants and soil since the 1970s. To prove the efficiency of phytomining as a source of metal, he rented a small plot of land in Malaysia. Every six to twelve months, farmers harvested 1 foot of the plant growth and squeezed or burned the metal-containing sap out of the plants. The sap was then purified and collected. This small plot produced about 500 pounds of nickel citrate, worth thousands of dollars. Nickel is a crucial component used in stainless steel, batteries for electric vehicles, and renewable energies.

     Baker and his colleagues are now scaling up to a 50 acre plot of land with the hopes of combating the mining industry. Mining industries have become increasingly controversial in the age of eco-friendly alternatives, but consumers are not slowing down their energy usage or the demand for these materials. Baker hopes that, in a decade, the demand for base metals and bare minerals can be sustained in part by phytomining. He acknowledges that phytomining might not be able to completely replace traditional mining, but it has many benefits. These plants grow in soils that are toxic to other plants, which allows more land to be productively used. Farmers on land with toxic soil would be able to make use of that soil with phytomining plants to create a new source of income.

     Dr. Baker is hoping this source of income can also sway nickel mining companies. Nickel mining requires coal and diesel fuels and creates acidic waste, toxic soil, and polluted waterways. These phytomining plants partially replace mines and, if planted in abandoned mines, can eradicate the negative byproducts of mining by cleaning up the soil. The revenue from these plants can be used as an incentive, along with the environmental cleanup aspect, to convince companies to consider the rehabilitation of mines through phytomining plants.

     While some people may be scared of metals and toxins that their soil might contain, Dr. Baker is refuting chemophobia by encouraging these communities to clean up their soil and make money doing it. Dr. Baker says that farmers can harvest phytomining plants on soil that contains 0.1% nickel for over 20 years. After two decades, this once-toxic soil will be devoid of nickel, but it can then be used as fertile land for traditional agricultural crops. Other opponents of phytomining have voiced concerns over a possible deforestation in order to plant the hyperaccumulating plants. These fears are unfounded because hyperaccumulating plants only grow in grassy areas that are toxic to most other plants, not in areas that could be deforested. Dr. Baker says that phytomining is “a way of putting back, rather than taking away.”

Gene Editing: Can the Utility Exceed the Fear?

Effective gene editing is becoming closer to reality as scientists develop new tools and methods to change our DNA. Arguably the most promising (and certainly the most well-known) recently developed tool for editing genes is CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats), a family of molecules which proven to be effective in controllably modifying specific segments of DNA. However, as the tool has become more known, many fears have arisen, concerning the medical and ethical dangers of gene modification. Do the potential benefits outweigh the potential risks? To answer this question, let’s first address what CRISPR is.

A computer representation of CRISPR in action

CRISPR is a two-part molecule: one part is a guide RNA to locate the desired gene, and the other is a DNA-cutting enzyme that performs the modification once on site. There are different variations being developed, but each one has those two key features. When these pieces work in tandem, they can cut and modify specific genes with a higher rate of precision, accuracy, and success than other methods.

Now, we should examine some of the fears that have risen alongside the popularity of CRISPR. The first is an ethical question on gene modification as a whole. At the most extreme end, some people’s minds jump immediately towards eugenics, the practice of purposefully controlling human reproduction to increase the occurrence of favorable genetic traits. One can see how the fear of effective genetic modification could be a step on a slippery slope in this direction, but again, this is generally the worst-case scenario and seems unlikely in the near future. A more subtle and reasonable fear is the idea that access to tools for choosing genes may lead to widening the gap between economic classes. After all, if a technology can ensure one’s children possess desirable traits, and this health technology is economically restricted (as it very well could be in the US), then new generations of the affluent could receive a measurable genetic advantage over others. This general fear has been characterized with the buzzphrase “designer babies.”

Pictured: Baby, non-designer

Before addressing the second fear, let’s discuss this first one, and why it may not pertain to CRISPR as much as it may seem at first glance. The traits that most are concerned about when discussing “designer babies” are broad, such as height, athletic ability, or intelligence. These kinds of attributes are actually very difficult to define genetically. A recent study attempted to find a genetic link for height and found that 697 genes accounted for only one fifth of height differences between subjects. Intelligence has eluded our attempts to define it sociologically and psychologically, much less quantify it genetically. Traits such as these would be extremely difficult to control, and while it is not off the table, it is certainly a long way off. The potential benefits of CRISPR would mainly be for genetic resistance to diseases, which are easier to quantify. However, if access to this is still economically restricted, it may still cause further class disparity for general health and life expectancy, so we must be wary of this danger as more about CRISPR is discovered. 

The second most common fear about the use of CRISPR is its potential danger when used on humans in general. Some fear that the technology is not efficient enough and may cause unintended cuts. Many also fear “off-target” effects; when one gene is modified for an intended effect, it may change something else unexpectedly. These fears have led many to be cautious about the use of CRISPR on humans, but some recent developments may help eliminate these worries.

A T cell, the supporting character of this CRISPR trial

In one recent trial, CRISPR was used to modify the T cells in 3 different cancer patients at the University of Pennsylvania, in an attempt to make the cells more effective at combating the cancer. The cells did not cure the cancer or become more effective at fighting it, but the trial was far from a failure. The most important result of the tests was that the cells passed the safety bar for clinical trials. The scientists facilitating the trials had a high success rate in gene cuts, the modified T cells survived for several months, and there were no adverse side effects. This is a big step towards further tests for CRISPR, suggesting that the method may be safer than originally thought. 

Recent findings on the safety of CRISPR bring us closer to eliminating the fears about its use. While it is still too early to make a definitive call, and every precaution should still be taken moving forward, it is good early evidence that the potential negative side-effects of CRISPR may be overblown. If development continues down this path, and CRISPR proves itself to be a reliable and effective way to modify genes against disease, its potential for improving human quality of life may outweigh any fears we have about using it sooner than we think.

Lab Diamonds vs Mined Diamonds: Are both Forever?

Are young couples beginning to prefer lab diamonds for their "forever" engagement rings?  Chemists can now make gem quality diamonds in the lab and young couples have taken notice.  Harriet Constable in a piece on the BBC "Future Planet" website notes that Millennials and now Generation Z – who together are the main purchasers of diamonds for engagement rings – are moving away from conventional diamonds, with nearly 70% of millennials considering buying a lab grown alternative." Both environmental and humanitarian concerns contribute to the young peoples interest.  Mining consumes a lot of energy.  On average recovering 1 carat of diamonds requires moving 250 tons of earth.  This is usually done with polluting diesel driven equipment.  Mining, particularly in developing countries where much of the mining is done, has involved abusive labor practices, and the proceeds have financed brutal gang warfare.  The industry has made efforts to curb these practices, but there is evidence they have not always succeeded.  On the other hand diamond mining provides employment in some otherwise impoverished areas.

Recovering 1 carat of diamonds requires move 250 tons of earth

Laboratory diamonds grow on a tiny seed crystal from high temperature carbon rich gasses.  The customer can buy directly from the laboratory so there is no question about complicated and possibly disturbing supply chains.  On the other hand the laboratory process is quite energy intensive.  Of course the energy from renewable sources is immediately adaptable to the process.

Making diamonds in the laboratory is quite energy intensive

On balance this is one case where young people are increasingly choosing chemistry over "natural."  While environmental and humanitarian concerns are certainly important Ms Constable notes that it might also be relevant that Meghan Markle has recently been seen wearing "a pair of glittering drop earrings embedded with diamonds that had been grown in a lab."