When it comes to 3D printing, the sky is the limit. As 3D printing technology continues to advance, applications can be as far reaching as airplane and automobile parts to medical devices and even anatomically correct, biocompatible models. Although 3D printing technology is developing at a rapid pace, the technology itself is not new. It emerged in the 1980s as a means of creating rapid prototypes. In recent years the applications for 3D printed models have evolved with the available hardware, software, and printable materials. Evolving technology, paired with the creative and innovative minds of scientists, engineers, and physicians, has been the launching pad for developments within 3D printing technology specific to healthcare. One way 3D printing technology is poised to create better patient outcomes is in creating an anatomically and patient-specific models to aid in surgery and medical procedures. With the capability to 3D ...
A California study shows that the most commonly produced plastics that are littered in the environment are also the ones that absorb the most chemicals, a finding that poses a greater risk for marine animals and those that eat them.
The absorption ability of these plasticscontinued for longer periods of time than previously thought. Chelsea Rochman, a doctoral student at University of California, Davis’ School of Veterinary Medicine, conducted the study for 12 months at five locations in San Diego Bay, the school reports. The study, whose results are published in the journal, Environmental Science & Technology, is the first controlled, long-term field experiment measuring the absorption of contaminants by the five most common plastics.
Those plastics are: 1) polyethylene terephthalate (PET), commonly used in water bottles; 2) high-density polyethylene (HDPE), used in detergent bottles; 3) polyvinyl chloride (PVC), commonly used in clear food packaging; 4) low-density polyethylene (LDPE), found in plastic shopping bags; and 5) polypropylene (PP), commonly used in yogurt containers and bottle caps.
The university explains how Rochman did her research:
Rochman and her colleagues deployed pellets of each plastic type in mesh bags tied to a dock at each study site. They retrieved them periodically to measure the plastics’ absorption of persistent organic pollutants.
“Consistently in our study, we found polyethylene [HDPE and LDPE] and polypropylene [PP] absorbed much greater concentrations of contaminants than PET or PVC, and those are the most commonly mass produced and consumed plastics,” says Rochman. “They are also the most commonly recovered as marine debris.”
The plastics with the highest absorption rates are also the most common. For example, HDPE, LDPE, and PP accounted for 62% of all plastics produced around the world in 2007, Rochman’s study found. PVC and PET made up 19% and 7%, respectfully, in the world. It was noted that while PVC did not take up proportionately as many pollutants as the other plastics, vinyl chloride is considered a carcinogen and toxic.
The researchers also were surprised at how long the plastics absorbed contaminates while in the environment, reports Mother Jones. They expected the plastics to absorb pollutants for several months. Instead, they were surprised to find that it would take 44 months for HDPE to stop absorbing pollutants.
“It surprised us that even after a year, some plastics would continue to take up contaminants,” Rochman says. “As the plastic continues to degrade, it’s potentially getting more and more hazardous to organisms as they absorb more and more contaminants.”
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