A industry survey by IBISWorld placed annual revenue from food trucks around $1.2 billion in 2009 and annual growth rates from 2007-2012 near 8.4% annually. Street Vendors in the US: Market Research Report estimated that there are over 15,500 individuals who serve food to diners in open-air locations.
Ozone depletion would magnify all of the effects of UV on human health, both positive (including production of Vitamin D) and negative (including sunburn, skin cancer, and cataracts). In addition, increased surface UV leads to increased tropospheric ozone, which is a health risk to humans.s explained above, the primary cause of ozone depletion is the presence of chlorine-containing source gases (primarily CFCs and related halocarbons). In the presence of UV light, these gases dissociate, releasing chlorine atoms, which then go on to catalyze ozone destruction.
Ozone is a gas that is present in the ozone layer in the stratosphere of the Earth. 1  There, it will absorb almost all ultraviolet light which is harmful to many organisms. The term Ozone depletion can refer to a number of distinct, but related phenomena: Since about the 1970s, there has been a decrease in total volume of the Ozone in the ozone layer, of about 4%, per decade. There are seasonal variations in the ozone layers; in springtime, there is less ozone in the ozone layer over the polar regions, esp. the south pole. This is generally known as ozone hole. In addition to these well-known stratospheric phenomena, there are also springtime polar tropospheric ozone depletion events. The details of polar ozone hole formation differ from that of mid-latitude thinning, but the most important process in both is catalytic destruction of ozone by atomic halogens.