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Pollution

Pollution and Environmental issues in the Finishing Industry

Pollution is the introduction of contaminants into an environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms . Pollution can take the form of chemical substances, or energy, such as noise, heat, or light energy. Pollutants, the elements of pollution, can be foreign substances or energies, or naturally occurring; when naturally occurring, they are considered contaminants when they exceed natural levels.

Heavy metals
Heavy metals are used in paints and it has raised concerns due to their toxicity at high levels of exposure and since they build up in the food chain.

Lead
Lead paint is paint containing lead as pigment. Lead is also added to paint to speed drying, increase durability, retain a fresh appearance, and resist moisture that causes corrosion. Paint with significant lead content is still used in industry and by the military. For example, leaded paint is sometimes used to paint roadways and parking lot lines. Lead is a poisonous metal that can damage nervous connections (especially in young children) and cause blood and brain disorders. Because of its low reactivity and solubility, lead poisoning usually only occurs in cases when the lead is dispersed, like when sanding lead based paint prior to repainting.

Chromium
Primer paint containing hexavalent chromium is still widely used for aerospace and automobile refinishing applications. Zinc chromate has been used as a pigment for artists paint, known as Zinc Yellow or Yellow 36. It is highly toxic and now rarely used.

Solvents
Volatile organic compound are gases emitted by various solids or liquids, many of which have short- and long-term adverse health effects.


Substitutes
Paint manufacturers replaced white lead with a less toxic substitute, titanium white (based on the pigment titanium dioxide) which was first used in paints in the 19th century. (In fact, titanium dioxide is considered safe enough to use as a food coloring and in toothpaste, and is a common ingredient in sunscreen.) The titanium white used in most paints today is often coated with silicon or aluminum oxides for better durability.