Showing posts with label ozone. Show all posts
Showing posts with label ozone. Show all posts

Tuesday, December 7, 2010

One Small Step Forward for the Environment, One Giant Step Backward for Human Health

I was saddened to read last week that the state of California has decided to in favour of replacing one ozone-depleting pesticide (methyl bromide) with another (methyl iodide) on the basis that the latter is much less destructive to that invisible shield above us that keeps most UV radiation away from our delicate skin. This is an improvement, but only in terms of halting ozone depletion (which, thankfully, has been occurring to a very small degree). If you take a step back and look at the bigger picture, this is what you see: methyl iodide, commonly used to sterilize the soil ahead of planting on industrial strawberry farms, is so carcinogenic that it is used to induce cancer in lab testing.


Since this pesticide does not linger on the berries themselves, it poses no apparent threat to consumers, but what of the farm workers and those living in nearby communities? Are we pausing long enough to think about the people who grow our food and live close to farms? Are we stopping to examine the package of strawberries available in supermarkets in December to find out where they come from? Is it necessary for us to eat fresh fruit out of season in light of our proximity to locally-grown berries in the summer and the existence of freezers in almost every home? Most importantly, where is the social justice in letting others face such enormous health risks when we would never do the same, just to be able to access any food, no matter how exotic, at any time of year?

For more, read Tom Laskawy's and Tom Philpott's articles in Grist.

Photo credit.

Friday, September 17, 2010

Good News: the Ozone Layer Is Recovering!

The United Nations published a study that found that the ozone layer is no longer thinning! In fact, the Antarctic ozone hole is smaller than it was in 2008. Granted, so far there is no proof that the ozone layer is increasing in volume, and there are estimates that we will have to wait another few decades (possibly the rest of this century for the polar regions in particular) before it fully recovers, but after my last post I think we ought to focus on the good news. So I'll say it again: the ozone layer is healing!

Time for a quick science lesson (based on Environment Canada and what I remember from high school). The ozone layer protects us from the sun's UV rays. The sun helps to create and break down molecules of ozone at just the right rates such that in a healthy atmosphere, the amount of ozone (and therefore the density of the ozone layer) remains constant. All is well in the stratosphere.

Enter human technology, circa 1970. We used chlorofluorocarbons (CFCs) in everything from fridges and air conditioners (as a coolant) to spray cans (as a propellant) to degreasers (as a solvent) without realizing that CFCs are ozone-depleting substances. The ozone layer started thinning out about 30 years ago, and polar regions suffered the greatest (the current hole is above the Antarctic). With less ozone, more solar radiation makes it to the earth's surface, resulting in greater incidences of skin cancer and cataracts, and the widespread loss of plant life, which has a huge effect on agriculture.

Thankfully, scientists from around the world found a way to trust one another and signed the Montreal Protocol in 1987 which paved the way for CFCs to be phased out of production and use. Unfortunately, ozone-depleting substances take years to reach the stratosphere, and some do not break down for centuries; this explains the slow rate at which the ozone layer is projected to recover. But it will eventually happen!

You can read more about the United Nations study here. In the meantime, stay sun safe. You may think the threat is minimal now that fall is around the corner, but UV rays still reach us when it's cold out. Consider using a facial moisturizer that contains sunscreen, since your face is the only part of your body that remains exposed to the sun all year round. Also, UV-blocking sunglasses are important even in the middle of winter when the sun reflects off of snow. It's hard to think about that in mid-September, but it's coming!

One last thing: remember that if the global scientific community found a way to come together on this issue (though it took years), then we can be hopeful that future agreements will be signed to help fight other sources of pollution.

I'm posting another cute animal picture to keep you optimistic (and to lessen my guilty conscience about being so doom-and-gloom in my last post).

3-day old Nigerian Dwarf goat babies Courtesy of http://cuteoverload.com