The smell of death is universally regarded as unpleasant and distressing. The potent odor is alarming when encountered unexpectedly and can be difficult to forget. But despite the powerful stench, exposure to the smell of a decomposing corpse does not directly cause specific diseases.
However, the odor does indicate the presence of potentially hazardous bacteria and biocontaminants that merit caution and proper professional cleanup. Read on to understand when decomposition odors start, what causes the smell, health risks of exposure, and how to safely remediate scenes contaminated by the stench of a dead body.
When Does the Smell of Decomposition Start?
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The pungent odor of a dead body begins just hours after death when the process of decomposition sets in. Once the flow of oxygenated blood stops and cells begin dying, bacteria naturally present in the body start breaking down tissue through putrefaction.
This causes the release of volatile organic compounds (VOCs) and gases associated with the stench of decay:
- Cadaverine – Organic compound with rotten flesh smell
- Putrescine – Organic compound with rancid odor
- Skatole – Foul fecal odor in high concentrations
- Hydrogen sulfide – Rotten egg gas
- Indole – Sewage-like musty odor
Within 24-48 hours, these gases diffuse into the surrounding environment and the smell of death becomes noticeable. The noxious fumes can be detected from a significant distance away.
As bacteria continue consuming the deceased’s tissues and bodily fluids, the smell intensifies. When a body bloats and ruptures due to built-up gases, greater amounts of odorous vapor are released. The longer the period between death and discovery of remains, the worse and more penetrating the stench.
What Causes the Smell of Decomposition?
The primary source of the repulsive scent of a rotting corpse is bacteria breaking down the body’s cells, fats, and proteins after death ceases the normal metabolic processes.
Microorganisms naturally living in the intestines, lungs, and other organs thrive on the dead tissues as an energy source. This bacterial growth depletes oxygen and releases VOCs as waste products of their digestion.
The main gases contributing to the smell of a dead body are:
- Cadaverine – From the breakdown of lysine amino acid
- Putrescine – From the breakdown of arginine amino acid
- Skatole – From the bacterial digestion of tryptophan
- Hydrogen sulfide – From the metabolic waste of sulfur-reducing gut bacteria
- Indole – From the decomposition of tryptophan
As these VOCs build up and diffuse out of the body, they collectively produce the sickly sweet, rotten stench associated with death and decay. The individual compounds lend distinct rancid, fecal notes to the overall odor.
The enzymes and acids released by bacteria also break down cell membranes and tissues, further accelerating decomposition and liberating gases. The warmer the conditions, the faster bacteria grow and the more pungent the smell of rotting death becomes.
Is the Smell of Decomposition Harmful?
The odor of a dead body itself is not classified as a biohazard. The stench and chemical compounds creating the smell are revolting but not directly hazardous in the concentrations emitted during decay.
However, the powerful scent of death is instinctively repulsive to humans and animals. Studies show that cadaverine and putrescine, in particular, trigger an innate threat response and avoidance behavior. This implies an evolutionary adaptation to associate the smell with danger and disease transmission.
While not inherently toxic, the smell of decomposition indicates the cadaver is teeming with bacteria, viruses, and biohazards that merit precautions. Bodily fluids can harbor dangerous pathogens spread through contact. The smell should be a warning sign to avoid direct exposure and the handle should remain with proper protection.
Factors Affecting the Smell of Decomposing Bodies
Many variables impact the rate at which a corpse emits odors and the persistence of the stench in the surrounding environment:
- Temperature – Heat speeds tissue breakdown and bacteria growth, worsening smell.
- Moisture – Fluids encourage putrefaction. Dry climates slow decay.
- Trauma – Violent deaths can accelerate the decomposition of odors.
- Manner of death – Infection, toxins, or existing tissue damage affect the rate of decay.
- Accessibility to insects/scavengers – Accelerates breakdown and spread of contamination. Can move remains and release gases.
- Size of remains – Larger bodies take longer to decompose and smell.
The potent odor of decay also permeates porous materials like carpeting, upholstery, drywall, and ventilation ducts. Lingering stench and biocontaminants may continue emanating from these surfaces long after the body’s removal.
Professional remediation is required to fully eliminate odors and hazardous microbial growth. The smell of death can stubbornly persist for years if decomposition scenes are not properly decontaminated.
Health Risks of Exposure to Decomposition Odors
There are some risks associated with inhaling the pungent smell of rotting death:
- Nausea – The sickening odor can cause vomiting and dry heaves.
- Anxiety – The stench triggers primal aversion and can induce trauma.
- Respiratory irritation – VOCs and gases may irritate airways and lungs.
- Headaches – Revolting smells commonly trigger headaches and migraines.
The biggest danger, however, is the presence of invisible hazardous bacteria and biocontaminants signaled by the smell of a dead body. Airborne pathogens and contact with contaminated surfaces, fluids, and insect carriers can lead to:
- Serious infections – Especially for those with weakened immune systems.
- GI illnesses – From fecal bacteria like salmonella and E. coli.
- Respiratory illness – From inhaling pathogens into lungs.
- Dangerous mold exposure – Some molds release toxic spores during decomposition.
If the remains explode due to built-up internal gases, there is an especially high contamination risk. The released vapors and expelled bodily fluids can travel far and widely disseminate hazards.
Professional Cleanup and Odor Removal for Decomposition
The overpowering stench and potential hazards posed by a decomposing body necessitate proper cleanup and odor remediation by qualified professionals. Lack of proper precautions can result in secondary contamination and the spread of dangerous bacteria.
General guidelines for trauma scene remediation:
- Seek professional assistance – Do not attempt cleanup yourself without training and PPE.
- Avoid exposure – Exit the scene and ventilate the area. Cordon off to prevent access.
- Remove remains – Only trained forensic personnel should handle biological materials.
- Employ PPE – Including hooded coveralls, gloves, foot covers, respirators.
- Disinfect surfaces – Use products registered to kill pathogens. Avoid bleach.
- Manage porous materials – May require removal or remediation.
- Contain ventilation – Turn off HVAC units, and block ducts during cleaning.
- Eliminate lingering odors – Via thermal fogging, ozone treatment, enzyme neutralization.
- Verify decontamination – Surface testing to confirm hazards removed.
Prompt intervention gives the best chance to fully eliminate potentially hazardous contamination and persistent, traumatizing decomposition odors.
The smell of a decomposing corpse triggers an instinctual human aversion. And for good reason — the noxious odor indicates the presence of hazardous microbial growth feeding on bodily tissues after death.
While not directly harmful, the stench should prompt precautions to avoid contact with contaminants and professional remediation. Prompt, proper cleanup and odor elimination are essential after discovering a decomposed body to restore safety and habitability.