Gaseous Pollutants – Definition, Examples, History & More – Art Conservation and Restoration Glossary

I. What are Gaseous Pollutants?

Gaseous pollutants are substances in the air that can have harmful effects on human health, the environment, and cultural heritage objects. These pollutants are typically in the form of gases or vapors that are released into the atmosphere through various human activities and natural processes.

Gaseous pollutants can include a wide range of substances, such as sulfur dioxide, nitrogen oxides, ozone, volatile organic compounds (VOCs), and carbon monoxide. These pollutants can come from sources like vehicle emissions, industrial processes, agricultural activities, and natural sources like volcanoes and wildfires.

II. Common Types of Gaseous Pollutants

Some common types of gaseous pollutants include sulfur dioxide (SO2), which is produced by burning fossil fuels like coal and oil, and nitrogen oxides (NOx), which are emitted from vehicle exhaust and industrial processes. Ozone (O3) is another common gaseous pollutant that forms when sunlight reacts with pollutants like VOCs and NOx in the atmosphere.

Volatile organic compounds (VOCs) are a diverse group of chemicals that can be emitted from sources like paints, solvents, cleaning products, and vehicle emissions. Carbon monoxide (CO) is a colorless, odorless gas that is produced by incomplete combustion of carbon-containing fuels.

III. Sources of Gaseous Pollutants

Gaseous pollutants can come from both human activities and natural processes. Human sources of gaseous pollutants include vehicle emissions, industrial processes, power plants, agricultural activities, and residential heating and cooking. Natural sources of gaseous pollutants include volcanic eruptions, wildfires, and biogenic emissions from plants and trees.

IV. Effects of Gaseous Pollutants on Artwork

Gaseous pollutants can have damaging effects on artwork and cultural heritage objects. Sulfur dioxide and nitrogen oxides can react with moisture in the air to form acids, which can corrode metal objects and degrade organic materials like paper, textiles, and wood. Ozone can cause fading and deterioration of pigments in paintings and prints.

Volatile organic compounds (VOCs) can contribute to the formation of indoor air pollution, which can lead to discoloration, staining, and embrittlement of artwork and artifacts. Carbon monoxide can also have harmful effects on artwork by accelerating the degradation of organic materials and causing discoloration.

V. Methods for Monitoring Gaseous Pollutants in Conservation Environments

There are several methods for monitoring gaseous pollutants in conservation environments to assess the levels of pollutants and their potential impact on artwork and cultural heritage objects. Air sampling can be used to collect samples of air from indoor spaces and analyze them for gaseous pollutants using techniques like gas chromatography and mass spectrometry.

Passive sampling devices, such as diffusion tubes and badges, can be deployed in conservation environments to monitor gaseous pollutants over an extended period of time. Real-time monitoring instruments, like photoionization detectors and gas sensors, can provide continuous measurements of gaseous pollutants in indoor spaces.

VI. Strategies for Mitigating Gaseous Pollutants in Conservation Settings

There are several strategies for mitigating gaseous pollutants in conservation settings to protect artwork and cultural heritage objects from degradation. Improving ventilation and air filtration systems can help to reduce the levels of gaseous pollutants in indoor spaces by increasing the exchange of outdoor air and removing pollutants through filtration.

Controlling sources of gaseous pollutants, such as by using low-emission materials and products, implementing pollution prevention measures, and reducing energy consumption, can help to minimize the impact of pollutants on artwork and artifacts. Implementing conservation strategies like encapsulation, isolation, and monitoring can also help to protect sensitive objects from gaseous pollutants.