A newly published report is highlighting the negative environmental and health impacts of plastics.

In an overview appearing in the journal Reviews on Environmental Health, Rolf Halden, a researcher at Arizona State University’s Biodesign Institute, together with co-author, ASU student Emily North, detail both the risks and benefits of plastics and describe strategies to mitigate their negative impacts through reconsideration of plastic composition, use and disposal.

“We are in need of a second plastic revolution,” says Halden.  “The first one brought us the age of plastics, changing human society and enabling the birth and explosive growth of many industries. But the materials used to make plastics weren’t chosen judiciously and we see the adverse consequences in widespread environmental pollution and unnecessary human exposure to harmful substances. Smart plastics of the future will be equally versatile but also non-toxic, biodegradable and made from renewable energy sources.”

While plastics fulfill many needs in the public health arena (where they are found in items including absorbable sutures, prosthetics and engineered tissues), Halden shows that the benefits of global plastics use can come at a steep price in terms of both human and environmental health. Continuous contact with plastic products, from the beginning to the end of life has caused chemical ingredients—some with potentially harmful effects—to form steady-state concentrations in the human body.

In recent years, two plastic-associated compounds have been singled out for particular scrutiny due to their endocrine-disrupting properties: bisphenol A (BPA) and di-(2-ethylhexyl)phthalate (DEHP). Studies of bioaccumulation have shown that detectable levels of BPA in urine have been identified in 95 percent of the adult population in the U.S. and both BPA and DEHP have been associated, through epidemiological and animal studies, with adverse effects on health and reproduction. These include early sexual maturation, decreased male fertility, aggressive behavior and other effects. Concern over BPA exposure, particularly for highly vulnerable members of the population, has recently led the U.S. Food and Drug Administration to place a ban on BPA use in infant bottles, spill proof cups and other products intended for infants and toddlers.

Similar issues exist with DEHP, a plasticizer found in polyvinyl chloride (PVC). Because this additive is not tightly bound to the plastics in which it is used, the potential exists for DEHP to leach out and enter the body, causing unwanted exposure and affecting health. Both animal and human studies suggest DEHP may produce harmful effects, including insulin resistance, increased waist circumference and changes to male and female reproductive systems.

Halden recommends a thorough life-cycle assessment of plastics-based products to identify safer, more sustainable replacement materials that reduce adverse effects to the environment and human health from plastic consumption.

“Many current types and consumption patterns of plastics are unsustainable, as indicated by harmful plastic components circulating in our blood streams and multiple giant garbage patches of plastic debris swirling in the world’s oceans. Continued use of plastics into the future will require us to redesign these indispensable materials of daily life to make them compatible with human health and the ecosystems we rely on,” says Halden.

Some newer plastics are biodegradable, but the rest must be incinerated, disposed of in landfills, or recycled. All of these methods have drawbacks and carry environmental risk, as the new study explains.

Biodegradable plastics may break down in the environment into smaller polymer constituents, which may still pose a risk to the environment. Incineration liberates greenhouse gases associated with climate change. Land-filling of plastics, particularly in the enormous volumes now produced, may be an impractical use of land resources and a danger exists of plastics constituents entering the ground water. Finally, recycling of plastics requires careful sorting of plastic material, which is difficult. Recycled plastics tend to be of lower quality and may not be practical for health care and other applications.

As Halden explains, the problems posed by plastics need to be addressed on several fronts, and current research offers significant hope for improvements to human and environmental health. Better biodegradable plastics are now being developed using carbon dioxide and carbon monoxide compounds and applying metal complexes as catalysts.

The technique provides a double benefit, binding unwanted greenhouse gases, while avoiding the competition with the human food supply. (Conventional bioplastics are made with plant sources like corn and molasses.) One application would be to replace BPA-containing epoxy resins lining metal food cans, thereby dramatically reducing BPA exposure while also sequestering 180 million metric tons of carbon dioxide (greenhouse) emissions.

Rolf Halden has been appointed to lead a new effort to protect human health and critical ecosystems, called the Center for Environmental Security (CES) at Ariziona State University. The goal of the Center is to protect human populations and the planet by detecting, minimizing and ultimately eliminating harmful chemical and biological agents through engineering interventions.

Source: ASU press release by Richard Harth, Science Writer, The Biodesign Institute