The time taken for a body to decompose can vary greatly due to a wide range of factors that can affect the process. Perhaps the most significant factor in the rate of decomposition is temperature and environment. Warmer temperatures will accelerate the process of decomposition whereas colder temperatures will slow the process down and, if cold enough, stop it altogether. The temperature will equally affect insect succession, which will ultimately affect how quickly the body is broken down.

Environmental conditions will equally affect the species of insect present in the area, in turn having an effect on the state of the corpse depending on the species colonizing the remains. A dry and windy environment can dehydrate a cadaver, resulting in mummification. The amount of protection a body has will also play a role in the rate of decomposition. For instance, a body swaddled in blankets or buried under a few feet of soil will be significantly less exposed than a naked, unburied cadaver exposed to the elements. A protected body may also limit insect activity, resulting in a slower rate of decomposition if insects cannot easily access the corpse, in addition to retaining body heat.

If a body is left submerged in water the rate of decomposition will typically be much slower due to the low temperatures and levels of oxygen, unless the corpse is able to float to the surface where insect colonization can occur. When a dead body is left exposed, it will inevitably attract scavengers which may have an effect on the apparent rate of decomposition. Although insect colonization on remains is reasonably well understood and estimations on time since death can be made by studying these, the cause of death can affect insect succession and in turn the state of decomposition. For instance, a corpse with gaping open wounds may introduce insects into areas of the body sooner than typically expected, resulting in the body appearing to be more decomposed.

If a body was burned the skin and tissue may be charred and dried out, rendering it unsuitable for microbial growth and certain insect colonization. However conversely fire could cause injuries which ultimately expose the body further, accelerating the decomposition process. Though not a common factor that must be taken into account, certain drugs in the body of the deceased have been known to affect decomposition in terms of insect activity. For example, the presence of cocaine has been shown to speed up development of insects, thus having an effect on the state of the corpse.

Prior to death: cocaine can exert a variety of effects. The major acute effects producing pathological conditions resulting in increased circulating catecholamine levels. Increased catecholamines can produce vasoconstriction. The lesions can include acute hemorrhages and infarction in the brain. Ischemic changes in the heart from small artery narrowing and sclerosis lead to contraction band necrosis of the myocardium and possible sudden death. Combining cocaine use with ethanol use can compound the myocardial damage.

– I. Keränen