Matt Herod

Matt Herod is a Ph.D Candidate in the Department of Earth Sciences at the University of Ottawa in Ontario, Canada. His research focuses on the geochemistry of iodine and the radioactive isotope iodine-129. His work involves characterizing the cycle and sources of 129I in the Canadian Arctic and applying this to long term radioactive waste disposal and the effect of Fukushima fallout. His project includes field work and lab work at the André E. Lalonde 3MV AMS Laboratory. Matt blogs about any topic in geology that interests him, and attempts to make these topics understandable to everyone. Tweets as @GeoHerod.

Emerging Contaminants: The Rough Teenagers

Emerging Contaminants: The Rough Teenagers

In geochemistry I see the term “bad actors” used more often than it should be to describe well-known environmental contaminants. “Bad actors” refers to contaminants we see frequently in the environment and know have significant environmental or human health effects. Think mercury, nitrates, lead, arsenic, sulphur dioxide, etc.

However, this article is on the up and coming contaminants that are just starting to achieve awareness in the environmental community so I thought calling them rough teenagers was an apt play on words. Feel free to call me out for my use of rampant hyperbole. Nonetheless, the contaminants/classes of contaminant described here are starting to cause major environmental problems and accompanying angst for environmental scientists, regulators and companies. They are certainly starting to appear more frequently in the scientific literature as the academic community is alerted to their presence and potential effects, which results in an increase in publications exploring their environmental behaviour and impacts.


Pharmaceuticals are a major emerging contaminant. It seems like hardly a day goes by without another article on pharmaceutical products in major water bodies or how they pass through water treatment plants. The way a pharmaceutical product ends up in the environment is simple. We take them, pee out the excess which ends up in the water treatment plant or septic system and then is released to the environment. These drugs still retain their efficacy, at least to some degree, when they enter the environment and therefore can induce huge impacts throughout the ecosystem as they act on organisms much smaller and much different to humans.

Microbeads and Personal Care Products

This is a trendy one. Microbeads and similar additives to cosmetics and shampoos have really caught the attention of the media and their environmental impacts have not yet been fully understood. Microbeads are tiny, tiny pieces of recycled plastic, usually polyethylene or similar petrochemical plastics, that are added to personal care products to give them an abrasive feel when used. They make your shampoo feel like it’s rubbing/cleaning your scalp or skin. However, their environmental impact when you wash your shampoo down the drain is where the problem with microbeads starts. Their small size, less than 5mm and commonly much smaller than that, means they can pass through water treatment systems and enter freshwater bodies and the ocean. Once circulated within these waterbodies they are ingested by fish, birds and other aquatic life posing a threat to their health. In fact, the threat of microbeads and the fact that their concentration has increased in large water bodies so rapidly has led to their ban in many nations. Hopefully, we’ll be able to take microbeads off this list soon!

A sample of microbeads collected from Lake Erie. (Source)


When you hear about element 34, Se, you might think of it as a helpful micronutrient, dandruff killer or it’s namesake, Selene, the Greek word for the moon. Unfortunately, it is much more harmful to the environment than we previously realized. The toxicity of selenium relates to the fact that it is a teratogen for fish and is even toxic for humans at higher doses. This means, that it leads to birth defects in fish and can lead to the disease selenosis in humans. The concentration at which it induces birth defects is also much lower than previously realized. Compounding selenium’s high toxicity is the fact that it is quite mobile in the environment and is easily transported in groundwater and surface water making it very difficult to control. Selenium is often released to the environment from mines as it co-occurs with a wide variety of other elements, such as lead, nickel, uranium, gold, and coal.


I see articles on this come up all the time, particularly about silver and copper nanoparticles, but there are others as well. It seems that the research community is kind of playing catch up in terms of assessing the transport and effect of nanoparticles on the environment, but I’ve started to see lots of articles on them now. Nanomaterials are particles that have a size range of 1-100 nanometres (10^-9 to 10^-7 m). They are used for an ever expanding variety of applications at the moment including coatings to add strength, keep your smelly socks from smelling, in electronics, in medecine, etc. The list is huge. However, once these nanomaterials have served their purpose or during their use they can be released to the environment. Once in the environment at higher concentrations these nanoparticles, often made of silver, carbon, titanium, cerium and other metals, can be ingested and inhaled by people and animals or enter the aquatic environment and expose fish and other aquatic biota. The effects that they have vary widely and are just starting to be understood but some types, such as silver, may affect plankton and algae, the basis upon which the aquatic food chain is built.

The COLT. A hockey stick that has a Ni, Co nanomaterial coating that is supposed to make it more resistant to breaking. Sadly, mine broke after many hard games, but not enough goals.

Rare Earth Elements

Rare earth elements (REE’s) such as cerium, dysprosium, lanthanum, etc. are being mined in greater quantities than even before to enable the production of cell phones and computers. Their widespread use has led to a boom in rare-earth element exploration and mining around the world as well as their relatively recent appearance in the litany of environmental contaminants. As newcomers, their effects are not yet fully understood, although given the increase in mining, research on the environmental effects of REE mines is forging ahead (I’m not sorry about the pun). Environmental exposure to REE’s has been implicated in a wide variety of human and ecological health effects  such as cardic and respiratory issues. The mining of REE’s can also release a wide variety of other toxic elements such as arsenic, lead and cadmium. Furthermore, REE ores are often also enriched in radioactive elements, such as uranium and thorium, which can make REE mine wastes a radiological concern. If care is taken during the mining stage, however, REE’s can be mined safely.

One of the booming uses of REE’s is in electronics

These are just a few of the emerging contaminants I have seen gaining traction flipping through the literature. There are loads more unfortunately. As we develop new and better technologies the unintended consequence is that the waste products or products themselves may pose an environmental threat that we do not predict or understand in order to bring the product to market. It usually falls to the scientific community and regulators to bring awareness of the effects these contaminants have and propose solutions. Every action has a reaction, and the development of new industries and new technologies often results in environmental effects that can take many years to discover and resolve. That said, by being aware of these emerging threats to the environment it is possible to take steps to reduce their harm before it is too late. The very brief overviews above do not do justice to each category and the complexity of their environmental transport and effects; particularly as studies in the natural environment are uncommon and most toxicity information is based on lab tests.

There are a lot of other new and not so new contaminants that are still cycling through the environment. There are also some success stories where problems were recognized and fixed so I don’t mean to imply that all hope is lost. If you can think of some additional “rough teenagers” that I did not bring awareness to here please post them in the comments section!


Photo of the Week

Photo of the Week

Keepin’ then comin’! This weeks photo is brought to you by Immageo as per usual. It can be found: here

The image was taken by Dmitry Tonkacheev, IGEM RAS, Moscow, Russian Federation.

Dmitry writes, “This is Co-bearing sphalerite, synthesised using gas transport method at 850C looks like the Christmas Tree. Although presented intergrowth of crystals was made in the laboratory, there are some natural samples, that comes from Africa. Green sphalerite from Congo can be used as jewellery.”

I have to chip in that incorporating Co into minerals can often lead to some very unsusual colours. For example, cobaltoan calcite is brilliant, neon pink.

Quartz over Malachite on Cobaltian Calcite

Cobaltoan Calcite from Katanga, Congo. (Source)

Photo of the Week

Photo of the Week

This amazing picture above was taken by Mikhail Varentsov, Lomonosov Moscow State University, Moscow, Russia. It can be found here. Mikhail writes “Melting summer sea ice is separated to pieces by the net of cracks, and their edges have amazing light-blue color, which is in contrast with white ice surface and deep blue sea water. Photo made during NABOS-2015 expedition.”

What this photo really reminds me of is the recent records relating to Arctic sea ice that have been broken. And, sadly, I don’t mean record highs. For a full discussion on Arctic sea ice status check out the Arctic Sea Ice blog. Long story short though this winter has broken all records for loss of Arctic sea ice, following last years record lows. These past two record breaking years are extremely alarming and the repercussions of such low levels of sea ice will be felt throughout the North and will affect the people and animals that rely on the sea ice.

Photo of the Week – Salt Coral

Photo of the Week – Salt Coral

The photo posted below is a really cool one. Interestingly, enough I have been getting into podcasts lately. They are great during my bus ride to and from work every day. One of the podcasts that I like is Neil de Grasse Tyson’s Star Talk Radio. Anyway, the other week Star Talk had a pretty good discussion about salt and the role it has played in developing human history. Check out the episode in two parts here. Arguably as one of the most important economic minerals of all time, although it may not seem so today.

That said, having read the book Sugar, Salt and Fat I would argue that salt retains its title as the most important of all economic minerals even to this very day! Anyone else have an opinion on this?

I digress though. The image below shows an incredible salt concretion on the shore of the hypersaline Dead Sea that has been formed by sea spray that has evaporated creating this magnifcent shape. Despite the title it is not actually coral.

Walking along the shoreline of the Dead Sea, you can find some magnificent objects, like this coral made of salt. Combine that with the beautiful scenery and amazing lighting at dawn and you get this amazing photo. Source - Salt Coral by Zachi Shtain

Walking along the shoreline of the Dead Sea, you can find some magnificent objects, like this coral made of salt. Combine that with the beautiful scenery and amazing lighting at dawn and you get this amazing photo. Source – Salt Coral by Zachi Shtain


Get every new post on this blog delivered to your Inbox.

Join other followers: