Just a note to Anti-Commie – these images may not have been Photoshopped. I studied photography in college for a couple of years, and it doesn’t matter whether you are using film or digital, nearly all high quality images are “manipulated” for contrast and exposure, intensity or lack or intensity in the photograph’s colours. I did colour negative printing as well as black and white, and colouration can be manipulated/altered printing “traditional style” colour prints. This kind of image manipulation went in on colour magazines for years prior to the invention of Photoshop.
They occur mainly in the form of sulphur dioxide. It is produced in large quantity during smelting of metallic ores and burning of petroleum and coal in industries, thermal plants, home and motor vehicles. In the air, SO 2 combines with water to form sulphurous acid (H 2 SO 3 ) which is the cause of acid rain. It causes chlorosis and necrosis of vegetation. Sulphur dioxide, above 1 ppm, affects human beings. It causes irritation to eyes and injury to respiratory tract. It results in discolouration and deterioration of buildings, sculptures, painted surfaces, fabrics, paper, leather, etc.