Tuesday, October 23, 2018

Microplastics Discovered In Human Stools Across The Globe In 'First Study Of Its Kind'

Researchers monitored a group of participants from 8 countries across the world with results showing that every single stool sample tested positive for the presence of microplastic and up to 9 different plastic types were identified.

Microplastics have been found in the human food chain as particles made of polypropylene (PP), polyethylene-terephthalate (PET) and others were detected in human stools, research presented today at the 26th UEG Week in Vienna reveals.

Researchers from the Medical University of Vienna and the Environment Agency Austria monitored a group of participants from countries across the world, including Finland, Italy, Japan, the Netherlands, Poland, Russia, the UK and Austria. The results show that every single stool sample tested positive for the presence of microplastic and up to nine different plastic types were identified.

When exposed to light, plastics break down into small pieces through a process known as 'photodegradation.' These small bits of plastic, known as microplastics, make up the majority of items found in the so-called 'Pacific Garbage Patch,' where they float suspended in the water column.
File:Microplastics (7656713582).jpg
Credit: NOAA Marine Debris Program / Wikimedia Commons

Microplastics are small particles of plastic less than 5mm and are used in various products for specific purposes; as well as being created unintentionally by the breaking down of larger pieces of plastic through weathering, degradation, wear and tear. Microplastic may impact human health via the GI tract where it could affect the tolerance and immune response of the gut by bioaccumulation or aiding transmission of toxic chemicals and pathogens.

The pilot study was conducted with eight participants from across the globe. Each person kept a food diary in the week leading up to their stool sampling. The diaries showed that all participants were exposed to plastics by consuming plastic wrapped foods or drinking from plastic bottles. None of the participants were vegetarians and six of them consumed sea fish.

The stools were tested at the Environment Agency Austria for 10 types of plastics following a newly developed analytical procedure. Up to nine different plastics, sized between 50 and 500 micrometres, were found, with polypropylene (PP) and polyethylene terephthalate (PET) being the most common. On average, the researchers found 20 microplastic particles per 10g of stool.

Lead researcher Dr. Philipp Schwabl, who is presenting the findings at the 26th UEG Week, commented: "This is the first study of its kind and confirms what we have long suspected, that plastics ultimately reach the human gut. Of particular concern is what this means to us, and especially patients with gastrointestinal diseases. While the highest plastic concentrations in animal studies have been found in the gut, the smallest microplastic particles are capable of entering the blood stream, lymphatic system and may even reach the liver. Now that we have first evidence for microplastics inside humans, we need further research to understand what this means for human health."

Global plastics production has increased substantially from the 1950s and continues to grow every year. For their many practical characteristics, plastics are pervasive in everyday life and humans are exposed to plastics in numerous ways. It is estimated that, through pollution, 2-5 % of all plastics produced end up in the seas. Once in the ocean, plastics are consumed by sea animals and enter the food chain where ultimately, they are likely to be consumed by humans. Significant amounts of microplastic have been detected in tuna, lobster and shrimp. Beyond that it is highly likely that during various steps of food processing or as a result of packaging food is being contaminated with plastics.

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Luke Paskins
Spink Health

Asian Elephants’ Math Skills Rival Humans

 Asian elephants demonstrate numeric ability which is closer to that observed in humans rather than in other animals. 

Experimental evidence showing that Asian elephants possess numerical skills similar to those in humans was developed by lead author Naoko Irie of SOKENDAI (The Graduate University for Advanced Studies) in Japan. In a study published in the Springer-branded Journal of Ethology, Irie and her colleagues found that an Asian elephants' sense of numbers is not affected by distance, magnitude or ratios of presented numerosities, and therefore provides initial experimental evidence that non-human animals have cognitive characteristics similar to human counting. 

Authai, the elephant,  using touch screen
Credit: Springer

Previous research has shown that many animals have some form of numerical competence, even though they do not use language. However, this numerical ability is mainly based on inaccurate quantity instead of absolute numbers. In this study, the researchers aimed to replicate the results of previous research that already showed that Asian elephants have exceptional numeric competence.

Irie and her colleagues developed a new method to test how well the animals can judge relative quantity. They successfully trained a 14-year old Asian elephant called Authai from the Ueno Zoo in Japan to use a computer-controlled touch panel. The programme was specifically designed to examine the cognition of elephants, so that any unintended factors potentially influencing the results could be ruled out. Authai was presented with a relative numerosity judgment task on the screen, and then had to indicate with the tip of her trunk which one of the two figures shown to her at a time contained more items. These ranged from 0 to 10 items, and contained pictures of bananas, watermelons and apples. The fruit were not all presented in the same size, to ensure that Authai did not make her choices purely on the total area that was covered with illustrations per card.

Authai was rewarded whenever she chose the figures featuring the larger number of items. This she did correctly 181 out of 271 times – a success rate of 66.8 per cent. Her ability to accurately pinpoint the figure with the most fruits on it was not affected by the magnitude, distance or ratio of the comparisons. Authai’s reaction time was, however, influenced by the distance and ratio between the two figures presented. She needed significantly more time to make her selection between figures where relatively smaller distances and larger ratios were presented.

“We found that her performance was unaffected by distance, magnitude, or the ratios of the presented numerosities, but consistent with observations of human counting, she required a longer time to respond to comparisons with smaller distances,” explains Irie. “This study provides the first experimental evidence that nonhuman animals have cognitive characteristics partially identical to human counting.”

According to Irie, this is not an ability that the Asian elephant shares with the two species of African elephants. She says that because the species diverged more than 7.6 million years ago, it is highly probable that each developed different cognitive abilities.

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Citation: Unique numerical competence of Asian elephants on the relative numerosity judgment task.
Naoko Irie, Mariko Hiraiwa-Hasegawa, Nobuyuki Kutsukake. Journal of Ethology, 2018; DOI: 10.1007/s10164-018-0563-y