Bacteria, Eating Snow and Climate Change
We all know (or should know) that eating dirty or yellow snow is a big “no-no”. Those of us who are parents (and live in regions where there are regular snowfalls) teach our children this lesson as quickly as possible. That said, should parents worry when their children eat new or freshly falling snow because it contains air-borne bacteria?
Last week, a group of scientists at Louisiana State University reported in.jpg)
Science magazine that there may be a relationship between ice-nucleating, air-borne bacteria and global rainfall patterns. For those of you who don’t know, the formation of ice in clouds is required for snow and most rainfall. Although dust and soot particles serve as ice nucleation particles, bacterial ice nuclei are capable of catalyzing freezing more quickly at much warmer temperatures and their presence in the atmosphere may affect the processes that trigger precipitation. Results from the Science study suggested that bacteria like Pseudomonas syringae, which have long been know to serve as nucleators and induce ice formation, are widely distributed in the atmosphere and likely play critical roles in influencing the amount of rain that falls at various locations in the world–pretty cool new stuff for those of us interested in global warming and climate change in general. Therefore, it surprised me when I saw that lay newspaper reporters chose to “cherry pick” data from the paper to suggest to Americans that even freshly fallen snow contains large numbers of bacteria and that, perhaps, parents should be careful when they allow their children to eat snow!
As a card-carrying microbiologist and seasoned science educator, I want to assure all of you that eating freshly fallen snow will not cause disease in you or your children. The types of bacteria found in the atmosphere, and ultimately in snow, are not human pathogens and don’t cause disease. Thankfully, in a story entitled “Study: Driven snow isn’t all that Pure” that appeared in my local paper (The Trenton Times)– a member of the American Academy of Pediatrics Committee on Environmental Health was quoted as saying ; “We eat stuff that’s covered with bacteria all the time, and for the most part, it is killed in the stomach.” Another pediatrician, who is a member of the academy’s committee on infectious diseases, reinforced the claim that snow munching was not harmful and said “Children practically bathe in bacterial when they go to the playground and they won’t get anything from snow that they would not get from dirt.”
Although most of the stories about bacteria and snow munching that appeared in the lay media were “fluff pieces”, they did alarm some parents! As one mother said in the Trenton Times article: “When I heard bacteria, at first, I went “eeeewwww”. But as long as the kids eat snow as it’s falling, I think it is okay. I tell them not to eat it if it’s on the ground.” What was particularly troubling about her remark was her initial negative reaction to the mere mention of the word bacteria. Unfortunately, most Americans have little understanding about bacteria and the negative impressions that they have formed are based on the sensationalistic and often scientifically inaccurate pieces about “dangerous” bacteria and fungi (mold) that often appear in print media and on television.
In my opinion, America’s negative attitude and poor understanding of science is a consequence of ongoing, misguided science reporting that has plagued this country for years. Although the American lay news media is mostly responsible for this, scientists are also complicit because of their unwillingness or inability to publicly speak out on important scientific issues and problems.
I believe that scientists are obliged to do everything in their powers to ensure that lay science reporting is fair and balanced and that the correct scientific messages reach the American public. Our failure to act will surely jeopardize the future of American science–something that we Americans can ill afford. Enough said–have a plate of snow on me!
Until next time….
Good Luck and Good Job Hunting!!!!!!!
