Poisons have been used as a means for murder since the beginning of written history. As man became more civilized and criminal investigation more clever, poisons allowed an almost untraceable way to get rid of enemies or even unwanted husbands or wives.
In many cases, poisoning occurs when people neglect the phrase, “everything in moderation.” Certain gases, such as carbon monoxide, become dangerous in high concentrations. Some of us may be slightly more familiar with alcohol poisoning. Heck, even slightly uncooked meat can cause food poisoning via salmonella bacteria, which affects 1 in 6 Americans every year. Apparently, we like our steaks as rare as they can get.
Most poisons operate in a common methodology: a biochemical enzyme is inactivated, which then creates a cellular effect. The final result is a physical and observable increase or decrease in the speed of certain body processes. When we endure prolonged stress of poisoning and struggle to restore homeostasis, also known as our bodies’ attempts at stabilizing our internal state, we experience symptoms like nausea, vomiting, dizziness, and coughing%20may%20experience%20increased%20sweating.)
So what exactly is a poison and how does it work from a chemistry standpoint?
Poisons are compounds that when ingested, absorbed, injected or inhaled cause disruption of normal body function usually through chemical reactions or activities on the molecular scale.
The lethality of poisons is given on a scale called the LD50 which is the lethal dose for 50% of the population. Even substances not thought of as poisons can be lethal if taken in improper dosages.
There are four pathways by which poisons enter the body:
- Ingestion (Gastrointestinal Tract)
- Inhalation (Lungs)
- Dermal/Topical (Skin)
- Injection (intravenous, intramuscular, intraperitoneal)
Not all pathways are equally effective. The speed with which a poison can act is dependent on the pathway it takes into the body.
The pathways are listed below from fastest to slowest:
- Intravenous (into a vein) injection
- inhalation
- intraperitoneal (into the body) injection
- intramuscular (into the muscle) injection
- ingestion
- topical (onto the skin) absorption
Some poisons are not fast acting no matter how they are administered. Poisons are also categorized by their speed of action:
| Acute | < 24hr | usually 1 exposure |
|---|---|---|
| Sub-acute | 1 month | repeated doses |
| Sub-chronic | 1-3mo | repeated doses |
| Chronic | > 3mo | repeated doses |