Say no to drugs!

In my previous blog I touched upon the presence of Ethinyl Estradiol 2, a synthetic hormone commonly used in the contraceptive pill, being present in marine systems, and how they can alter the endocrine system of aquatic life. It may or may not come as a surprise to you that traces of illicit drugs, such as cocaine and MDMA (ecstasy) have also been found in waste water systems, as well as pharmaceutical drugs like ibuprofen and various antibiotics.

A study, reviewed the effects these drugs have on aquatic organisms, and the results weren't great. Many of the chemicals released from these drugs, in particular, from cannabis and cocaine, showed DNA damage, even at low levels of concentration - 40ng/L concentration was shown to effect D. polymorpha (a type of mussel) in this way. They also looked into illicit drugs found in river sites, and found concentrations up to 25ng/L of MDMA and 17ng/L of cocaine. Alarmingly high in comparison to the results found in the River Thames back in 2008, where cocaine ~4ng/L and MDMA ~4ng/L.
The results are in nano-grams per litre. Though this is a small measuring, if you take into account that the river has many currents and tidal flows from the rivers' source, which dilute the water, the amounts are likely to be concentrated higher in urban areas.

Many traces of antibiotics were also found in this study which can also be toxic to acquatic organisms. But it's not just animals that are at risk, humans are too. We're at a time where it is of growing concern how many antibiotics we're using in the world, with the risk of antibiotic resistance ever increasing. These illicit drugs and chemicals have the potential of ending up in our drinking water. Overtime, daily consumption of nano amounts can have a great impact.

So think twice before taking any drug! And maybe buy a water filter system for your home tap, just to be safe!

Ladies, stop taking the pill!

Ethinyl Estradiol 2 (EE2) is a synthetic hormone, that is a bioactive oestrogen, used commonly in medication (the contraceptive pill for example), as well as livestock (to improve the productivity). EE2 is also used in aquaculture, to farm single-sex populations of fish.

A conceptual diagram of how EE2 enters the acquatic system through various sources

It is of growing concern to the environment because of its ability to be absorbed into organic matter, concentrate in biota, and accumulate in sediments. They enter the environment generally through wastewater systems, and by manure.
I mentioned how EE2 can be used in aquatic systems, to control the growth and population of farmed species. The problem with this, is there's a lot of 'waste' that spills into surrounding areas of water. Approximately 70% of the chemical 'spills' out due to over feeding of fish; this also triggers areas around the world where EE2 is more commonly found in the water. This translates to local freshwater being contaminated, a problem because humans drink this water- it has been found but not confirmed that the chemical can cause a decrease in fertility, and may cause cancer.

Many past studies concluded that these EE2 hormones can be highly toxic to exposed aquatic species. These are some of the effects:
-An increase of plasma vitellogenin (a gene) in male and female fish
-An increase of intersex fish
-A decrease in egg and sperm production
-A reduction in gamete quality
-Male fish changing sex
-Reduced fertility
It also has the ability to change the behaviour of a species. Reyhanian et al. (2011) proved that EE2 affected the shoaling behavior in adult male zebra fish. Those that were exposed to higher concentrations had a greater reduction in swimming activity, and spent a lot of time near the surface, compared to fish exposed to much smaller doses.
Amphibians and mammals have also been proven to be affected by EE2. The Northern leopard frog was seen to have altered sex ratios of tadpoles, with a dominance of females. The metamorphism process was also delayed by up to two weeks. Controlled experiments on mice led to the conclusion of a retardation in their growth.

EE2 has the ability to be absorbed into organic matter, so there are often higher concentrations of the hormone found at the bottom of water systems, in the sediments. They can actually encourage the EE2 to settle due to the hydrophobic properties of the sediments, with concentrations being 1000 times higher than levels recorded at the surface of the water. This is problematic, because it also means that the hormone can stay in the environment for a longer period of time, especially if sediments deposit on top, creating beds. Benthic invertebrates are left extremely vulnerable because of this. Labadie and Hill (2007)

So we know that EE2 can be some what problematic to the environment, but it's not that easy to get rid of it. We cannot just ban them, because they have become an important factor in everyday lives. Studies have found that EE2 can be removed from the environment completely, by the use of microbes and bacteria, by the process of biological degradation.  But it's not easy to introduce a bunch of bacteria into water systems without complications- this would be expensive, and we do not know what the long term effects are. Filter systems can be put in place in sewage systems, but this too is costly, not to mention the amount of energy that would be used to do so. I think it's important to study the sediments of water basins; if they hold much higher concentrations of EE2, finding a way to clean them may help reduce the amount of EE2 dramatically.

Cigarettes... An overlooked entity?

I recently saw a powerful advert by the Food and Drug Administration, encouraging people to stop smoking. It got me thinking about how harmful they are, not just to humans... to the environment.

It comes as no surprise that it can impact the environment in some way. We are blowing out thousands of chemicals, from arsenic and ammonia to hydrogen cyanide, which aren't exactly a good thing. All of these chemicals have the potential to be absorbed by the globes' water, damaging fish and micro-organisms.

But it's not just the toxic chemicals that are harming the environment - production and waste is a major problem.

600 million trees are cut down every year to make the papers for the 6 trillion cigarettes that are produced globally each year. A length of 4 miles of paper is used to produce cigarettes each hour! And machines are used to make them, powered by coal no doubt.

Countries where tobacco is grown, like Uganda, have experienced massive areas of deforestation. According to an article by IRIN Africa, the country has lost almost a third of its trees in the past 20 years, and unless we stop exploiting these forests, by 2050 there won't be any left! This will have a huge detrimental impact on the country in many aspects; agriculture will decline, the majority of the population will suffer, farmers won't be able to harvest, water resources will be scarce, diseases will spread, and animals will disappear, with some species becoming extinct.

Then there's the cigarettes themselves. Globally, two thirds (about 4.6 trillion) of all cigarettes smoked are being tossed into the environment. Butts and filters are the most common waste product being found and cleaned up on beaches world wide. A handful of studies have suggested that chemicals absorbed into the butts and filters, such as pesticides and arsenic are seeping into water, affecting aquatic life. Butts that are discarded on the roadside also contaminate the environment by releasing chemicals, and heavy metals such as lead and copper. 

The majority of filters are made of paper and rayon wrapping, which controls the airflow. Glue is also used to hold the cigarette and filter together, and a variety of alkali metal salts are found in cigarettes to help keep them burning. Plastic is also used in many of the filters, which is non-biodegradable - a problem which you should now be familiar with if you've been keeping up to date with my blogs!

All of these elements pose a massive threat, because they can remain in the environment forever. (Novotny et al 2014)

It's not just small organisms and marine life that are effected, humans are too. These chemicals can contaminate the food we eat, and the water we drink. Below is a great diagram I found that shows some of the ways in which humans are at risk:

People need to be made more aware about the impacts of cigarettes on the environment, not just to our own health. As an ex-smoker, I definitely didn't think twice about these threats, or what damage flicking a butt out of my car window can actually do. At least with some awareness, maybe it can encourage people to discard butts and packets properly (in the designated bins).