Group 1

Cyanide: Cyanide contains a carbon atom connected

to a nitrogen atom, hence the chemical formula CN.

Cyanides can be manufactured but they also occur in nature.

In the natural environment, cyanide containing chemicals are produced by a wide range of organisms and plants as part of their normal metabolism. Bacteria and fungi are known producers of cyanide.

A few species of centipedes, millipedes, insects, beetles, mothsand butterflies secrete cyanide for defensive purposes in repelling predators such as toads and birds.

What is hydrogen cyanide?At room temperature, hydrogen cyanide is a

volatile, colorless -to-blue liquid (also called hydrocyanicacid). It rapidly becomes a gas that can produce death in minutes if breathed. Hydrogen cyanide is used in making fibers, plastics, dyes, pesticides, and other chemicals, and as a fumigant to kill rats. It is also used in electroplating metals and in developing photographic film

What is Cyanide Poisoning?A condition that results from exposure to

cyanide.

The lethal dose of Hydrogen Cyanide in Humans is 1mg/kg.

Causes:Fires: Smoke inhalation during the burning

of common substances such as rubber, plastic, and silk can create cyanide fumes

Plants containing cyanide include apricot pits and a type of potato called cassava. Fortunately, only chronic or massive ingestion of any of these plants or pits can lead to serious cyanide poisoning.

Industrial: Occupational exposures du  Metal extraction in mining, electroplating in jewelry production, photography, plastics and rubber manufacturing.

CausesMedical - Cyanide exposures can

result from alternative and standard medical treatments.

Sodium nitroprusside, a medication used in the treatment of hypertensive emergencies, contains five cyanide groups per molecule.

Acute Cyanide PoisoningCNS signs and symptoms usually develop

rapidly. Initial symptoms are nonspecific and include

excitement, dizziness,nausea, vomiting, headache, and weakness. As poisoningprogresses, drowsiness, tetanic spasm, lockjaw, convulsions,hallucinations, loss of consciousness, and coma may occur

After systemic poisoning begins, victims may complain of shortness of breath and chest tightness. Pulmonary findings mayinclude rapid breathing and increased depth of respirations. Aspoisoning progresses, respirations become slow and gasping; abluish skin color may or may not be present. Accumulation of fluid in the lungs may develop.

Chronic Cyanide PoisoningExposure over long period of time

Symptoms will have more gradual onset

Chronic Cyanide Poisoning:chronic low exposure to hydrogen cyanide

can cause neurological, respiratory,c ardiovascular, and thyroid effects.

CNS symptoms include(headache, dizziness, nausea, and bitter almond) -low-, moderate-, or high-exposure through work histories.

Chronic Cyanide Poisoning:Some symptoms persisted for 7 months or

more after exposure.

None of the workers had palpable thyroid gland abnormalities, but clinical tests revealed decreases in vitamin B12 absorption and folate levels and statistically significant increases in thyroid-stimulating hormone levels

Physical and Chemical Properties:

Hydrogen cyanide (AC) is a pale blue or colorless liquid below 78° F and a colorless gas at higher temperatures. It has a bitter almond odor and is highly volatile and flammable at room temperature.

Sodium cyanide and potassium cyanide are white powders which may have a bitter almond-like odor. In the presence of moisture, either can form hydrogen cyanide.

Cyanogen compounds can generate cyanides. Cyanogen chloride (CK) is a colorless liquefied gas that is heavier than air and has a pungent, highly irritating odor. It is soluble in water and organic solvents.

Cyanide Sources

Some of the common plants that contain cyanide are:

cassavasweet potatoes cornlima beans almonds,Radishes cabbage,

CauliflowerBroccoli turnipsLettucekidney beansand it can be found in

the pits or seeds of cherries, plums, apricots, pears and apples.

Sources:Smoke inhalation from structural firesMaterials such as wool, silk, and synthetic

polymers contain carbon and nitrogen and may produce cyanide gas when exposed to high temperatures 

intravenous antihypertensive sodium nitroprusside.

Uses:Cyanide and cyanide-containing compounds

are used in :pesticides and fumigants plastics,photographic developing mining. Dye, textile and pharmaceutical industries

also use cyanides. Cyanide is also used in the manufacture of

nylon, plasticglass, perfume, soaps, fertilizers, paints

Importance:

primary mechanism of cyanide excretion is formation of thiocyanate within the liver.

catalyzes the conversion of cyanide to thiocyanate, and thiocyanate is then excreted via the kidneys

In general, Cyanide has a high affinity to form complex with metal

In side the body, CN ions form complexes with metallic cations at the catalytic sites of several

important enzymes thus inhibiting their function. The most severe, life-threatening clinical effects are caused by binding to the ferric (+3)ions

of mitochondrial cytochrome oxidase (cytochrome a-a3). Cytochrome a-a3 mediates the transfer of electrons to molecular oxygen, the final step in oxidative phosphorylation.

Cyanide binds with cytochrome oxidase, the enzyme responsible for oxidative phosphorylation, and paralyzes cellular respiration. Because the tissues cannot use oxygen that is delivered, aerobic metabolism ceases. 

the tissues cannot use oxygen that is delivered, aerobic metabolism ceases