麻豆影视

Human testicles contain microplastics and nanoplastics at levels three times higher than animal testes and human placentas, a new small study found.

鈥淭hese plastics are often nano-scale, typically less than half a micron in length and maybe like 20 to 200 nanometres in width,鈥� said toxicologist Matthew Campen, coauthor of the study that published May 15 in the journal .

鈥淭hey look like little shards, tiny broken bits from very, very old plastics,鈥� said Campen, a regents鈥� professor of pharmaceutical sciences at the University of New Mexico in Albuquerque.

Such minuscule particles can invade individual cells and tissues in major organs, experts say, interrupting cellular processes and potentially depositing  such as , , , , and .

Endocrine disruptors interfere with the human reproductive system, leading to genital and reproductive malformations as well as female infertility and a decline in sperm count, according to the Endocrine Society.

In fact, sperm counts in parts of the world, including the United States, have declined by at least 50 per cent over the past 50 years, the society

鈥淭his is an eyes wide open situation right now,鈥� Campen said. 鈥淲e鈥檙e just now realizing how much plastic is in our bodies. We need a surge of research around this topic to confirm or deny a role for microplastics in driving infertility, testicular cancer and other cancers.鈥�

'Action is desperately needed now'

The new study tested 23 preserved testes from cadavers who were ages 16 to 88 at the time of their death, then compared the levels of 12 different types of plastics in those testicles with plastics found in 47 dog testes.

鈥淭he levels of microplastic shards and types of plastics in human testes were three times greater than those found in dogs, and the dogs are eating off the floor,鈥� Campen said. 鈥淪o it really puts in perspective of what we鈥檙e putting in our own bodies.鈥�

, one of the most widely used plastics in the world, was the predominant type of polymer in both species, followed by PVC, or polyvinyl chloride, another commonly used chemical that can contain including cadmium and lead. Phthalates, called  鈥� because they are so common, are added to consumer products to make the plastic more flexible and harder to break.

Researchers expected to find more plastic shards in the testicles of older men in the study, but that wasn鈥檛 the case, Campen said.

鈥淚t seems that in peak reproductive years for men, which is from 20 to 45, there are higher levels of plastics, which then begin to decline after the age of 55,鈥� he said. 鈥淭his suggests the human body can eliminate these plastics.鈥�

But there is a downside. The finding also suggests that the increased energy needs of a younger testicle may 鈥渁lso pull more plastic into that organ,鈥� Campen said.

鈥淎dd to that the fact that the number of plastics we鈥檙e exposed to is doubling at a rate of every 10 to 15 years,鈥� he said. 鈥淪o what鈥檚 going to happen in 15 years when we are exposed to twice the amount or 30 years when we are exposed to four times the amount? That is why action is desperately needed now.鈥�

The American Chemistry Council, an industry association, told CNN in a that plastics 鈥渉elp protect us, improve healthcare outcomes, and contribute to a more sustainable world.鈥�

鈥淧lastic makers have a  for all US plastic packaging to be reused, recycled, or recovered by 2040,鈥� said Dr. Kimberly Wise White, the council鈥檚 vice president of regulatory and scientific affairs.

More plastics than placentas

Researchers also compared the testes results with microplastic levels found in an earlier study on 62 human placentas, the organ that provides oxygen and nutrients to a developing fetus in the womb.

In that , led by Campen, researchers found microplastics at levels of 6.5 to 790 micrograms per gram of tissue in all the placenta samples studied.

鈥淚n testes, the levels of plastic was three times as much as we saw in placentas,鈥� Campen said. 鈥淏ut you have to consider that the placenta only has a life of about eight months.鈥�

The latest study isn鈥檛 the first report to find plastics in reproductive tissue. A team of Beijing-based researchers found microplastics in six human testes and 30 semen samples in a , while tiny plastics can impact sperm count and contribute to hormone and other disruptions in male sexual organs.

In , researchers have found plastic chemicals in the brain, heart, liver, kidney and lungs of the developing fetus 24 hours after the pregnant mother ingested or breathed in plastic particles. Other  has shown that micro- and nanoplastics may cause oxidative stress, tissue damage and inflammation in cells, while such particles may alter heart rate and impede cardiac function.

How to limit plastic in your life

There are steps one can take to reduce exposure to phthalates and other chemicals in food and food packaging products, according to the American Academy of Pediatrics鈥� policy statement on .

鈥淥ne is to reduce our plastic footprint by using stainless steel and glass containers, when possible,鈥� said Dr. Leonardo Trasande, director of environmental pediatrics at NYU Langone Health, in a .

鈥淎void microwaving food or beverages in plastic, including infant formula and pumped human milk, and don鈥檛 put plastic in the dishwasher, because the heat can cause chemicals to leach out,鈥� said Trasande, who is also the lead author for the American Academy of Pediatrics鈥� policy statement on food additives and children鈥檚 health.

鈥淟ook at the recycling code on the bottom of products to find the plastic type, and avoid plastics with recycling codes 3, which typically contain phthalates,鈥� he added.

Cut down on the use of disposable plastics, suggests the , an environmental advocacy group. Other suggestions include bringing reusable bags to the grocery store. Invest in a zippered fabric bag and ask the dry cleaner to return your clothes in that instead of those thin sheets of plastic. Bring a travel mug to the local coffee store for takeout and silverware to the office and cut back on plastic cups and utensils.