Pollutants and biological agents
Pollutants such as sulphur dioxide and
nitrogen dioxide, which combine with moisture in the air to form sulfuric
and nitric acids, are highly deteriorative to paper. Ozone—a
gaseous pollutant formed by heated car exhaust (particularly in the summer)
and given off by copy machines—causes oxidation, which embrittles paper.
Peroxides, paint and cleaning supply fumes, solvents, and acidic fumes
initiate deteriorative chemical reactions which stain and degrade papers.
Biological agents that can damage archival
materials include mold, mildew,
insects, and rodents. Temperatures above 75°F (24°C), humidity above 60 percent, darkness, and poor air
circulation encourage mold growth. Mold will permanently stain paper, causing
both deterioration and cosmetic damage.
Insects that are attracted to cellulose and other organic substances
include cockroaches, silverfish, termites, and beetles.
The damage they do is irreversible.
Rodents, such as rats, mice, and squirrels, can nibble away at collection
items, or eat them in their entirety. They like to use shredded paper
as a nesting material. Their droppings are also corrosive and can leave
permanent stains. |
