Shanna Swan, director of the University of Rochester's Center for Reproductive Epidemiology, conducted studies that found an association between pregnant women's exposure to phthalates and altered genital development in their baby boys. Also, people with the highest exposure to BPA have an increased rate of heart disease and diabetes, according to one recent study. Animal tests studies of PBDEs have revealed the potential for damaging the developing brain and the reproductive system.
Yet the effects on human health remain largely unknown. To help shed more light on the issue, the report recommends more sophisticated human studies.
But testing humans for endocrine disruptors can be tricky because phthalates and BPA pass through the body so quickly. Deciding which chemicals to test and at what dose is also an issue. To date, most studies have addressed single chemicals, and there are limited data on the interactions between chemicals. Compounding the problem is the discovery that endocrine disrupting chemicals may have effects at doses lower than those used in the Environmental Protection Agency's standard toxicity tests.
Many researchers recommend studies that test pregnant women as well as their children. The National Children's Study will do just that by examining environmental influences on more than , children across the United States, following them from before birth until age Plastic's problems extend beyond the human body, according to the report. More than one-third of all plastic is disposable packaging like bottles and bags, many of which end up littering the environment.
Although the image of a bird tangled in a plastic necklace is by now burned into the public's eye, ingestion of plastic fragments is much more common. Once inside, plastic can pack a one-two punch by both clogging an animal's stomach and poisoning it with chemicals that have concentrated in the plastic. Some chemicals are then transferred to the food web when animals eat them.
More than species of animals have been documented to ingest plastic debris, including birds, fish, turtles and marine mammals, according to the report. Unfortunately, collecting data on plasticizers' impacts on wildlife suffers the same pitfalls as studying human health.
Still, there is already evidence that chemicals associated plastics might harm wildlife. For example, laboratory studies have shown that phthalates and BPA affect reproduction in all studied animal groups and impair development in crustaceans and amphibians.
Charles Tyler, a professor at the University of Exeter School of Biosciences in the United Kingdom and a senior author of the report, said that scientists have shown that "some of these chemical compounds are getting into the environment and are in some environments at concentrations where they can produce biological effects in a range of wildlife species.
Traveling from coast to coast, plastic can endure for thousands of years due to the reduced UV exposure and lower temperatures of aquatic habitats. Barnes demonstrates plastic's mobility with his account of a plastic sighting during an expedition to the Amundsen Sea where he took biological samples, the first there ever.
The Amundsen, located in the Pacific Sector of Antarctica, is the only sea in Antarctica with no research station on its coast and the nearest urban center thousands of miles away.
Plastic also serves as a floating transportation device that allows alien species to hitchhike to unfamiliar parts of the world, threatening biodiversity. Global warming further aids the process by making previously inhospitable areas like the Arctic livable for invasive species, which can be detrimental to local species.
For example, plastic items are commonly colonized by barnacles, tubeworms and algae. Along the shore of Adelaide Island, west of the Antarctic Peninsula, ten species of invertebrates were found attached to plastic strapping that was littering the ice.
Plastic is so resilient that even burying it deep within the earth doesn't keep it from impacting the environment. Currently it accounts for approximately 10 percent of generated waste, most of which is landfilled.
But, as the report notes, placing plastics in a landfill may simply be storing a problem for the future, as plastic's chemicals often sink into nearby land, contaminating groundwater. In addition, production of plastics is a major user of fossil fuels. Eight percent of world oil production goes to manufacturing plastics. As plastics grow in volume at a rate of about nine percent each year, the authors emphasize that tackling its problems means addressing its sustainability.
One solution is to treat plastic as a reusable material rather than as a disposable commodity that's quickly discarded. Plastic can cause harm to marine life and humans in three ways. Physical harm can be caused when animals become entangled in plastics and when animals eat plastic. Chemical harm can occur due to the toxic nature of the chemical additives associated with the manufacturing of plastics.
Some of the reporting of the potential harm caused by plastic can be misleading. It is important to respect the specificity of language used by the science community. There is much we know about the harm caused by plastics and much we do not know or is currently being studied. Over-exaggeration or over-statement of the harm caused by plastic may seem useful in the short-term to bounce people into action, but in the long-term exaggeration can lead to a lack of trust, and compound inertia.
It is also useful to reflect on whether we need to know everything before taking action. The scale of the plastics issue is such that we can choose to take action now. Scientists are finding plastic in every area of the ocean that they are looking, from the Arctic sea ice Peeken et al. The amount of plastic being produced is astonishing, with 8. The projections are that this rate of production will continue to soar to an annual production of 1.
In addition, the growing body of evidence is such that we can adopt the precautionary principle. This means that until we can show that plastic pollution is causing no harm, we should do as much as possible to limit its potential impact on marine and human health. Entanglement in plastic kills a range of marine life, including seals, turtles and sharks.
Strong evidence observed in marine environment, with entanglement shown to have caused death in marine species. Extent currently measured using computer modelling and accuracy being improved using citizen science reporting and apps.
Some media overstatement of the number of deaths caused by entanglement should not detract from the seriousness of the issue. Strong evidence base in the marine environment. There need to be more drinking facilities with extra convenience so that people are encouraged to reuse plastic bottles rather than throw them away.
By now you should know some of the effects that plastics have on the environment, but let's look specifically at plastic pollution. Plastic pollution causes harm to humans, animals and plants through toxic pollutants. It can take hundreds or even thousands of years for plastic to break down so the environmental damage is long-lasting.
It affects all organisms in the food chain from tiny species like plankton through to whales. Toxins work their way up the food chain when plastic is ingested and can even be present in the fish people eat.
Over the last 10 years, most people will have noticed the unnecessary overuse of plastic in packaging. We have already discussed the positive effects of reusing plastics, but there are some further actions that can be taken to reduce plastic packaging:. Coffee cups are a huge source of plastic pollution, as they contain a plastic paste known as polyethylene which helps the cup keep your coffee warm, but also prevents it from being recycled.
You can help the environment by using reusable cups, rather than plastic or paper. This reuse and refill model is starting to be employed in supermarkets and cafes. There is evidence that some recycling has ended up being shipped abroad and even some to Asia, where it has been dumped in the rainforest , rather than recycled. Progress has been made to reduce plastic usage since the introduction of fees in supermarkets. But, abroad there have been campaigns to ban plastic bags.
Several African countries, including Kenya, have banned plastic bags entirely. In Mauritius, they only use a dissolvable corn starch plastic bag in the supermarkets, even away from the tourist areas. We all are learning about the effects of plastic and there are huge steps to go in making a big difference.
Know someone that is eco mad? Perhaps one of our gift cards could be the perfect present for them. Lucy February 05, Maria Gonzalez February 05,
0コメント