Cyanide Spill Catastrophe
Cyanide spills & clean up infographic. By: Justin T
Brief Description of Cyanide
(e.g. NaCN). It is found in low amounts in nature, and can be found in some foods and plants such as almonds and cassava respectively. A majority of human exposure comes from the cigarette smoke. Due to its poisonous effects it has been used as a chemical weapon in WWI. In some gaseous forms, it is a toxic, colorless gas with what is described as a "bitter almond" odor.
Human and Environmental Hazards
Exposure
Humans can be exposed to cyanide through inhalation, ingestion and absorption of the skin and eyes. Toxicity to humans depends on the volume of exposure. Cyanide exposure is categorized at LC50 and LD50. The LC50 of cyanide is 100-300 parts per million, this will cause death in 10-60 minutes. As concentration rises, speed of fatality increases, for example if 2000 parts per million of cyanide is inhaled, death can occur in ~1 minute. The LD50 of cyanide for ingestion is 1-3mg/kg of body weight while the LD50 for skin absorption is 100mg/kg of body weight.
Effects on the body
Once the cyanide has reached the bloodstream it interferes with an enzyme, cytochrome oxidase that aids cells in the synthesis of adenosine triphosphate (ATP) which is used as energy for cells in the body. If the cytochrome oxidase is not working properly body cells can not utilize oxygen in the bloodstream, this can cause hypoxia and cellular asphyxiation. This lack of oxygen causes the cells to go from their normal means of aerobic metabolism to anaerobic metabolism (combustion of carbohydrates for energy), this causes lactate to accumulate in the bloodstream. This lactate build up, combined with hypoxia can lead to respiratory and cardiac arrest.
Symptoms
Cyanide exposure causes an array of mild to severe symptoms. Immediate symptoms include dizziness, headaches, weak and/or rapid pulse, deep, rapid breathing, nausea and vomiting. Larger exposures can cause more severe symptoms such as convulsions, low blood pressure, loss of consciousness, Respiratory failure, cardiac failure and death.
Environment
Cyanide is produced naturally in the environment from plants/fungi/algae and bacteria and does not have many adverse affects on the natural enviroment. Cyanide is also known to be released from incomplete combustion reactions of forest fires. The environment has means of handling and disposing the natural cyanide through reactions in the environment forming compounds and causing the cyanide to degrade.
Cyanide however, is toxic to most wildlife animals.
Aquatic Animals
Aquatic animals when exposed to cyanide (effects occur from ~5 - 7.2 micrograms per litre) experience weaker swim performance and hinders reproduction ability in some species of fish. More symptoms include delayed mortality, disrupted respiration, altered growth patterns and osmoregulatory (maintains fluid balance and electrolytes) disturbances. When concentration of cyanide reaches ~20 - 76 micrograms/L death causes death for many aquatic species.
Birds
The lethal dose for birds ranges from 0.8 - 11 mg/kg of body weight. Symptoms include panting, rapid blinking, salivation and lethargy. High exposure doses are followed by deep breathing developing into gasping and shallow breaths. Death occurs between 15 and 30 minutes after exposure. However birds that survived 1 hour after exposure usually live, speculation suggests this is due to rapid metabolism.
Mammals
Land mammals are more vulnerable to cyanide due to the amount of cyanide producing plants/bacteria etc in their ecosystem.
There is a huge variety of mammal wildlife, but the general lethal dose ranges from 2.1 - 10mg/kg of body weight. Symptoms of poisoning include muscle tremors, salivation, lacrimation (tear flow) sudden deification & urination, labored breathing, gasping, muscle incordination and convulsions.
It has been found that common livestock species (cattle, sheep, pigs, horse etc.) have a increased resistance to cyanide.
Despite being heavily present in the typical mammal environment, cyanide poisoning is uncommon and widespread due to two main factors; Cyanide is not naturally produced in significant, or toxic/lethal levels, and cyanide is not stored or accumulated in many kinds of mammals.
Baia Mare Cyanide Spill
Baia Mare Cyanide Spill
Baia Mare Cyanide Spill
Goals & Technology
Treatment
Chlorine and hypochlorite can be used to treat cyanide spills, but is not recommended in uncontained spills, as these compounds and reactions can cause further impact on the environment. Hydrogen Peroxide is commonly used.
Finally to ensure the safety of the public and others, if the cyanide spill reached for example a public area or water stream, a large area is then monitored for any possible hazards.
Reactions
B: NaCLO(aq) + NaCN(aq) → NaOCN(aq) +NaCl(aq)
Once the sodium cyanide has degraded to a more stable sodium cyanate, sodium hypochlorite is added again with water to create nontoxic sodium chloride, sodium bicarbonate and nitrogen gas
S: NaOCN(aq) + NaOCL + H20 → NaCl +NaHCO + N2
B: 2NaOCN(aq) + 3NaOCL + H20 → 3NaCl + 2NaHCO + N2
Benefits
Risks
Another risk is the emergency team or workplace personnel will have to manage the spill themselves. Without proper gear this could be a dangerous task, because if the cyanide spill is large enough to incur a notification, it has already reached LD levels.