Article fails to compare BPA levels found in sand, oceans to levels measured elsewhere.
An article in Science News describes concentrations of BPA in beach sand and ocean water, but misses the mark when putting the levels and sources into context.
Science News reporter Janet Raloff describes an important new finding from Katsuhiko Saido and his research group in Japan. Raloff reports that "fairly substantial quantities" of BPA have been measured both in seawater and in beach sand at 28 coastal sites sampled by Saido's team. The levels detected in seawater were reported to be in the range of 100 parts per billion (ppb), and levels reported in beach sand were "orders of magnitude higher," ranging from 50 to 100 parts per million (ppm).
Similar to previous reports, Saido also found that BPA leaches from polycarbonate baby bottles sampled from countries around the world. He found levels of 40 ppm from a bottle purchased in Italy, 102 ppm from a bottle purchased in China, and 11 ppm from a bottle purchased in the U.S. – a level that Raloff refers to as "measly."
Unfortunately, the concentrations found in seawater and beach sand and the levels leaching from baby bottles are not put into context to allow the reader to understand the significance of these concentrations. The levels detected in sand and baby bottles are much higher than those reported to cause effects in animal and lab studies, and therefore, may be of concern.
BPA has received a lot of attention, both in the press and from scientists, because of its widespread use and its growing list of possible health effects. People are exposed when it leaches into food and water from polycarbonate plastics and epoxy resins. Levels of 0.5 to 3 ppb are measured in human blood and urine samples from individuals in countries around the world.
As for levels, lower concentrations can cause effects. Hundreds of rodent studies indicate that exposure to low levels of BPA can affect the development of fetuses and neonates. Human cell studies find that levels as low as 1 ppb of BPA can have significant, detrimental effects on a variety of health endpoints. And levels from 2 ppb to 1 ppm are known to affect a wide range of laboratory and wild animals.
In comparison to the much higher levels detected in bottles from other countries, levels of 11 ppm in bottles from the U.S. may seem like a reason for celebrating. However, considering estimates that infants consume between 0.7 and 1 liter of infant formula each day from a bottle, these levels are not negligible.
In spite of the findings of significant levels of BPA leaching from polycarbonate baby bottles, Raloff reports that Saido "doesn’t think baby bottles, hard-plastic water bottles and the handles on screw drivers (to name a few polycarbonate products) are responsible for most of the BPA he’s turned up in the marine world." Instead, he thinks that the use of BPA-based paints on boats and ships are responsible for the high levels of BPA detected in beach sand and sea water.
Yet, Raloff goes on to say that "there’s probably a lot more polycarbonate out in the world than epoxy resins." The US National Toxicology Program estimates that 1.4 billion pounds of BPA are used each year in the production of polycarbonate plastics, and about a third as much (406 million pounds) are used in the production of epoxy resins. Other reports of large amounts of plastic littering the oceans, including "The Great Pacific Garbage Patch" that has been described in detail, suggest that plastics breaking down in the oceans are a significant source of BPA pollution.
Unfortunately, no other scientists were interviewed for this piece to offer any other views of the possible sources of contamination. Therefore, the significant levels of BPA measured in drinking water, rivers, soil, air and dust that are reported in dozens of other studies are not mentioned in this article. The finding of BPA in so many environmental samples suggests that a single source – such as ship paint – cannot explain its presence in seawater and sand. It is much more likely that BPA is leaching from a multitude of consumer products.
While the article presents a newly identified place for BPA contamination, readers would have benefited if levels were compared to those found in other environments and if another expert not affiliated with the research had been interviewed.
