5 Gyres - Understanding Plastic Pollution Through Exploration, Education, and Action

One of the issues 5 Gyres is concerned with beyond the sheer amount of plastics in the ocean is the relationship of plastics and dangerous chemicals. Because plastics are a fat, they attract pollutants present in the ocean environment from land runoff. For years, the world's strategy for dealing with chemical waste has been, 'dilution is the solution.' Of course this is a very short sighted mitigation strategy because ocean born chemical level continue to rise, even in very remote places. The stability of chemicals can be described in two ways: volatile or persistent.  Corexit, the stuff used to disperse the oil after the Gulf spill, is a volatile compound, meaning it's not stable, meaning it will breakdown quickly in the environment as it has very, very short half life. When I say, 'breakdown', that doesn't mean that the chemical is safe, it just means that when exposed to the environment it will breakdown into other compounds and so little is known about the 'interim' chemicals it creates, that determining its safety is very difficult. Those interim chemicals are called 'metabolites.'  Think of a molecule this way; and conjure an image of a sword in a sheath. Together, sword within sheath isn't dangerous, but when the sword is separated from the sheath, the sword by itself, is very dangerous.  This what chemicals do in the environment---now, in the case of Corexit, the analogy doesn't work, because it's more like a sword in a sheath covered by razorblades.  Do not only do you have to deal with the sword, you have to deal with all the razorblades. 

 

5 Gyres advisor Dr. Hideshige Takada runs a site called International Pellet Watch which was designed to engage citizen scientists to help answer the question, 'how toxic are plastics in various parts of the world?' Interested citizens can go to their favorite beach and collect nurdles (pre-production plastic pellets, which are ubiquitously present on beaches around the world) and send them Takada's team and they'll analyze your nurdles for chemical uptake and send you a report. FOR FREE. It's a very cool program, collecting data from some of the most remote places on the earth. Check it out.  That's exactly what 5 Gyres team member Leslie Moyer did when 5 Gyres landed in Uruguay last year.  Below the next picture is the report she received yesterday explaining the results on her nurdles. The good news is, her pellets had 

From International Pellet Watch:

Dear Leslie Moyer,

My name is Maybelline Yeo. I am a student of Prof. Takada who analyzed the pellet samples which you collected and sent. 

Considering the location, we suspected that the location is very remote and predicted low pollutant concentration there. 

As predicted the overall pollutant concentration levels are very low to almost non-detected. 

PCBs which are mostly used in electronics and industries have the concentration of 0.01 ng/g pellet which we would categorize as not locally polluted.  

Because PCBs can be remobilized in the environment and is susceptible to long range transport, hence it can be found anywhere in the world. 

With such low level detected, we can suspect that it was transported from other areas and that there are no local sources of PCBs contamination in the area. 

But the extremely low concentration can also suggest that the pellets collected were not exposed to the environment long enough to reach equilibrium concentration with the surroundings.

Considered as a remote location, Cabo Polonio, Uruguay has similar PCBs concentration with the other remote areas in which we have analyzed.

From the world map, you can observe that area such as Isla Cebaco, Panama (1.49ng/g pellet), Kahuku Beach, Hawaii (0.74 ng/g pellet) and Costa Rica (7 ng/g pellet) are also categorized as remote areas all shows concentration of 10 ng/g pellet or less.

However, should we focus on individual samples, we would get alarming result.  To consider piece-to-piece variability of contaminant concentrations, we analyzed 5 pools of pellets for each location and  choose median concentration among the 5 pools to get representative contaminant concentration.  When we use the median, the story is as above, i.e., the location (Cabo Polonio) is very clean.  

However, if we were to see the concentrations of PCBs in the individual pools, we have one pool with extremely high concentration of PCBs (i.e., 24 ng/g) in comparison to the other pools.  

This sporadic high concentration of PCBs should be taken into account from the view of ecotoxicology.  That is, this pool of pellets may give threat to marine organisms in Cabo Polonio. 

General level of pollution is very clean in the area and minimal exposure of PCBs to marine organisms through water and food web is expected.  

To the organism in the area, plastics may bring relatively high concentrations of PCBs.  Similar phenomena (sporadic high concentrations of contaminants) is observed in many remote sites.  Your sample has given us the strong confirmation.  Marine plastics is unique but more hazardous transport media of POPs (persistent organic pollutants) in marine ecosystem.     

While the concentration of DDTs and HCHs which are used as pesticide, the concentration for DDTs were not detected while concentration for HCHs were below levels of quantification. 

Both results were not significant. This suggests that these pesticides were not used in the vicinity recently. 

There was not much information about the sampling area which I could gather online except that it is a very remote place and there’s a very small town in the area with no electricity or running water. Also, that there are no roads leading to Cabo Polonio and that it is only accessible via foot or a 4x4. And based on observation using Google Earth, there was no sign of any anthropogenic activity around the area. But we cannot be absolutely sure about the situation there, hence please feel free to concur, correct or comment on the sampling site.

Should there be any questions regarding the analytical results, please do not hesitate to ask.

Sincerely,

Maybelline