Grease-proof packaging has helped make pizzas, burgers and tacos on-the-go a less messy proposition. However, a new study in the ACS journal Environmental Science & Technology Letters has found that some fast-food packaging from across the U.S. contains a variety of fluorinated compounds — a few of which have been linked to potential health effects.
According to the Agency for Toxic Substances and Disease Registry, some studies in humans have suggested that long-chain, per- and polyfluoroalkyl substances, or PFASs, are associated with developmental problems in children, decreased fertility and an increased cancer risk. In 2000, the U.S. started phasing out some long-chain PFASs, which had commonly been used in a wide range of products to make them stain-resistant or waterproof, for example. But other countries still produce them, and some manufacturers have replaced them with shorter-chain PFASs or variations of long-chain PFASs. The potential health effects of these smaller compounds are unclear, although preliminary studies have raised concerns. Previous research has shown that substances in food packaging can migrate into food and, when discarded in landfills, could contribute to elevated levels of PFASs in the environment. How much depends on type of PFAS, temperature and other factors.
To find out how widely used PFASs are in fast-food packaging, Laurel Schaider of the Silent Spring Institute and her colleagues tested more than 400 paper wrappers, paperboard containers and cups from fast-food restaurants across the U.S. They detected fluorine — an indication of fluorinated compounds — in nearly half of the food contact papers overall and 20 percent of the paperboard containers. Wrappers for Tex-Mex food, desserts and breads were the most likely to contain fluorine. A more detailed analysis of a subset of 20 samples found that perfluorooctanoic acid (PFOA), a long-chain PFAS currently being phased out in the U.S., was among the packaging compounds. Determining what the findings mean for consumers is difficult, however. The PFASs occurred at a wide range of concentrations, suggesting that some of them were not specifically added to the packaging but came from older, recycled materials or other undetermined sources. The researchers say this could lead to the persistence of some of the compounds, even if phased out, for many years to come.
The authors acknowledge funding from the National Science Foundation and the Silent Spring Institute.
A cheaper way to make a WHO-designated essential medicine
A fungal form of meningitis leads to more than 600,000 deaths in Africa every year and is responsible for 20 percent of HIV/AIDS-related deaths globally, according to the U.S. Centers for Disease Control and Prevention. An existing medicine could help curb these numbers, but its cost has been a barrier to access in some places. Now, scientists report in the ACS journal Organic Process Research & Development a more affordable way to make the drug.
The antifungal flucytosine has been available to patients in the U.S. for decades. In 2011, the World Health Organization (WHO) recommended that patients with Cryptococcal meningitis, an infection of particular concern to people with HIV/AIDS, take flucytosine in combination with amphotericin B as a first line of defense. Flucytosine is now on WHO’s Core List of Essential Medicines. However, the drug is not registered for use in many African countries, according to the non-profit Doctors without Borders, and where it is available, many patients can’t afford it. Currently, making the drug requires a multiple-step process that involves fluorination, chlorination, amination and hydrolysis from uracil. To help slash flucytosine’s price tag and improve its availability, Graham Sandford and colleagues at Durham University in the U.K. wanted to come up with a simpler, lower cost way to make the drug.
The researchers developed a one-step technique to make flucytosine out of readily available, naturally occurring cytosine. Their process involved simultaneously pumping inexpensive fluorine gas and a solution of cytosine in formic acid through a steel tube. This fluorinated all of the starting cytosine, and the researchers were able to isolate high yields of the resulting flucytosine by recrystallization. The researchers say the method should be simple to scale up for manufacturing and could help lower the drug’s cost. The one-step method has been successfully developed to pilot-scale by industrial collaborators Sanofi-Aventis and La Maison Européenne des Procédés Innovants in France.
The authors acknowledge funding from the Innovative Medicines Initiative, a joint undertaking between the European Commission’s Seventh Framework Programme and the European Federation of Pharmaceutical Industries and Association.
Peacock colors inspire ‘greener’ way to dye clothes
Peacock feathers, opals and butterfly wings have inspired a new way to color voile fabrics without the pollutants of traditional dyes.
“Fast fashion” might be cheap, but its high environmental cost from dyes polluting the water near factories has been well documented. To help stem the tide of dyes from entering streams and rivers, scientists report in the journal ACS Applied Materials & Interfaces a nonpolluting method to color textiles using 3-D colloidal crystals.
Dyes and pigments are chemical colors that produce their visual effect by selectively absorbing and reflecting specific wavelengths of visible light. Structural or physical colors — such as those of opals, peacock feathers and butterfly wings — result from light-modifying micro- and nanostructures. Bingtao Tang and colleagues wanted to find a way to color voile textiles with structural colors without creating a stream of waste.
The researchers developed a simple, two-step process for transferring 3-D colloidal crystals, a structural color material, to voile fabrics. Their “dye” included polystyrene nanoparticles for color, polyacrylate for mechanical stability, carbon black to enhance color saturation and water. Testing showed the method could produce the full spectrum of colors, which remained bright even after washing. In addition, the team said that the technique did not produce contaminants that could pollute nearby water.
The authors acknowledge funding from the National Natural Science Foundation of China, the Fundamental Research Funds for the Central Universities (China), and Dalian University’s Program for Innovative Research Team, Program for Liaoning Excellent Talents and Program for New Century Excellent Talents.