fluctuating between the two, can cause varying levels of deterioration for objects. Temperatures that are too high can lead to chemical and physical damage such as embrittlement, cracking, fading, and disintegration. Too high temperatures can also promote biological reactions like mold growth. Temperatures that are too low can also result in physical damages such as embrittlement and cracking. Temperature fluctuations can cause materials to expand and contract rapidly which causes stress to build up within the material and eventual deterioration over time. Pests Pests include microorganisms, insects, and rodents and are able to disfigure, damage, and destroy material culture. Both organic material and inorganic material are highly susceptible. Damage can occur from pests consuming, burrowing into, and excreting on material. The presence of pests can be the result of other deterioration mechanisms such as incorrect temperature, incorrect relative humidity, and the presence of water. Fumigation and pesticides may also be damaging to certain materials and requires careful consideration. Conservation science has aided in the development of thermal control methods to eradicate pests. Pollutants Pollutants consist of a wide range of compounds that can have detrimental chemical reactions with objects. Pollutants can be gases, aerosols, liquids, or solids and are able to reach objects from transference from other objects, dissipation in the air, or intrinsically as part of the object's makeup. They all have the potential to cause adverse reactions with material culture. Conservation science aids in identifying both material and pollutant properties and the types of reactions that will occur. Reactions range from discoloration and stains, to acidification and structural weakening. Dust is one of the most common airborne pollutants and its presence can attract pests as well as alter the object's surface. Research in the field informs conservators on how to properly manage damage that occurs as well as means to monitor and control pollutant levels. Physical forces Physical forces are any interaction with an object that changes its current state of motion. Physical forces can cause a range of damage from small cracks and fissures to complete destruction or disintegration of material. The level of damage is dependent on the brittleness or hardness of the object's material and the magnitude of the force being inflicted. Impact, shock, vibration, pressure, and abrasion are a few examples of physical forces that can have adverse effects on material culture. Physical forces can occur from natural disasters like earthquakes, working forces like