ANTIBIOTIC SUSCEPTIBILITY TESTING. Bacteria demonstrate two kinds of resistance to antibiotics, namely intrinsic resistance and acquired resistance. Intrinsic resistance means that the species was resistant to an antibiotic even before its introduction.
Radiation is naturally present in our environment, as it has been since before the birth of this planet. In addition, radiation can be produced artificially, as in medical x-rays and microwaves for cooking. Nonetheless, most people are not aware of all the natural and man-made sources of radiation in our environment.
During energy generation chemicals such as methane are released into the air as a result of oil and natural gas extraction. The combustion of coal and natural gas for electricity production causes the release of sulphur dioxide, nitrogen oxides and carbon dioxide into the air.