Copper (atomic weight 63.54) is ductile, lustrous, reddish metal (density 8.92 g/ mL). The main application of copper is in electrical industry (transformers, generators, and transmission of electricity). Pollution derives from copper mining, brass manufacture, electroplating industries and from the use of its compounds in agriculture. Copper is known as one of the highest mammalian toxic compounds; inhalation of copper containing sprays is linked with an increase in lung cancer among exposed workers. Copper sulphate is widely used as an algaecide in water supply reservoirs affected by blooms of blue-green algae.

The maximum acceptable copper in drinking water is 2 mg/L (WHO, 2008).

1.1.2 Lead

Lead (atomic weight 207.19) is a bluish-grey, soft, dense metal (density 11.34 g/ mL). The oxidation states are 0, +2, +4. Lead is extremely resistant to corrosion and is a poor conductor of electricity. Large quantities of lead, both as the metal and as the dioxide, are used in storage batteries. Lead is also used in cable covering, as ammunition, as electrodes, in solder and as roofing material. The metal is used as shielding from radiation, e. g. in x-ray rooms and nuclear reactors. Lead oxide is also used in the manufacture of fine crystal glass. Historically, lead was used in plumbing. Tetraethyl lead was used as an anti-knock agent in petrol, and as an additive in paints. These uses have been reduced recently because of environmental concerns about cumulative lead poisoning. Although lead is one of the most useful of all the metals, used since antiquity because of its wide distribution and its easiness to be extracted and to work with, it is also the metal that has the most damaging effects on human health. Environmental contamination by lead probably dates back to Bronze Age. It can enter the human body through the uptake of food (65%), water (20%) and air (15%). Human activities, such as fuel combustion, industrial processes and solid waste combustion contribute to the rise of lead concentrations in the environment. Lead interferes with a variety of body processes and is toxic to many organs and tissues including heart, bones, intestines, kidneys, and reproductive and nervous systems. It interferes with the development of the nervous system and is therefore particularly toxic to children, causing potentially permanent learning and behavior disorders. Occupational exposure is a common cause of lead poisoning in adults. Lead can reach water through the corrosion of pipelines in water transportation systems. WHO Guidelines limit for lead in drinking water is 0.01 mg/L (WHO, 2008).