Unfortunately, there is no simple and inexpensive way to monitor pollutants in cultural institutions. Because the effect of gaseous pollutants may differ according to the level of relative humidity and/or the presence of other pollutants, most existing methods use indicators (such as silver) that are sensitive to pollutants. The corrosion of these indicators demonstrates the presence of pollutants that may damage collections. These may be useful in institutions with specialized collections that are particularly sensitive to pollutants, such as photographs.
Other options include periodic sampling of air quality over the course of a year by a specialized company, a complicated and expensive option, or the use of instruments designed to measure levels of urban pollution (e.g., devices that pass air through a tube filled with a reactive substance, or electronic monitors that use corrosion detectors).