Toxicity of alcohol

VAIBHAV LAUR

The degree to which an alcohol can damage an organism known as toxicity of alcohol.

Toxicology  is a branch of biology, chemistry and medicine concerned with the study of the adverse effects of chemicals on living organisms.

Toxicity is the degree to which a substance can damage an organism.

The skull and crossbones is a common symbol for toxicity.

Toxicity can be measured by its effect on the target because individual have different levels of response to the same dose of a toxic substance.

Toxicology

ALCOHOL An alcohol is an organic compound in which (-OH) group is bound to a carbon atom..

Alcohol is a general term for a family of organic compounds.

Commonly encountered members include ::

1) Methanol 2) Ethanol 3) Isopropanol

In common speech word alcohol refers to ethanol.

ALCOHOL Ethanol is the alcohol found in alcoholic beverages.

Ethanol also called ethyl alcohol, pure alcohol, grain alcohol or drinking alcohol.

Alcoholic beverages have been consumed by humans since prehistoric times for a variety of hygienic, dietary, medicinal, religious reasons.

Properties of Ethanol

A clear volatile liquid.

Burns easily

Oxidizes easily

Soluble in water

Miscible in all proportions

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Type of Alcohol Distilled alcohol1)

A distilled beverage, spirit, or liquor is an alcoholic beverage produced by distilling.

Ethanol produced by means of fermenting grain, fruit, or vegetables.

Example- RUM, Vodka, Whiskey Brandy, Tequila etc

Fermented and undistilled alcohol

Type of Alcohol 2)

Alcoholic beverage produced by fermentating grain, fruit or vegetables.

Example- Beer(Fruit beer), Cigar(made of apple juice) Sake(fermenting rice) etc.

Alcohol

Illicit liquor Any alcoholic beverage made under unlicensed conditions is called illicit

liquor.

Alcohol Poisonous effects

Denatured spirit (mixture of ethanol and methanol) added by illicit brewers to save costs and in mistaken belief that it'll increase potency.  chemicals like organo-phosphorus compounds have been added to illicit liquor. Methyl alcohol is extremely toxic — 10 ml can cause blindness and 30 ml can cause death within 10 to 30 hours.

Antidotes Ethyl alcohol and fomepizole are antidotes, inhibiting metabolizing of methyl alcohol so that it passes through urine.

Alcohol in Blood vs Breath

The ratio of alcohol in blood to alcohol in alveoli air is 2100 to 1.

1 mL of blood will contain about the same amount of alcohol as 2100 mL of breath.

During the period of absorption, the alcohol concentration is higher in arterial blood than venous blood

Alcohol and Circulatory System Humans have a closed circulatory system consisting of a heart, arteries, veins,

and capillaries.

Alcohol is absorbed from the stomach and small intestines into the blood stream. Alcohol is carried to the liver where the process of its destruction starts.

Blood, carrying alcohol, moves to the heart and is pumped to the lungs.

In the lungs, carbon dioxide and alcohol leave the blood and oxygen enters the blood in the air sacs known as alveoli.

Then the carbon dioxide and alcohol are exhaled during breathing.

Alcohol Absorption

Alcohol is absorbed by simple diffusion into the blood.

Small intestine is the most efficient region for absorption because of its large surface area.

20-25% of a dose of alcohol is absorbed from the stomach.

75-80% is absorbed from the small intestine. Once absorbed, alcohol is oxidized in liver by alcohol dehydrogenase turned into acidic acid.

Presence of food in stomach (especially fatty foods) delays absorption.

 

Factors that Affect Alcohol Absorption

• Amount of alcohol consumed

• Time of consumption

• Body weight

• Rate of alcohol absorption

• Type of alcoholic beverage

• Presence of food in stomach

Elimination

The liver eliminates 95% of the alcohol through metabolism (oxidation via acetaldehyde & acetic acid to carbon dioxide & water).

Remain eliminated through excretion in breath, urine, sweat & saliva.

Absorbed alcohol is passed through the liver by circulating blood. ADH (alcohol dehydrogenase) converts the alcohol to acetaldehyde(acetaldehyde is a highly toxic substance).

Aldehyde dehydrogenase converts acetaldehyde to acetate ion. Acetate enters blood stream & is ultimately oxidized to CO2.

Blood alcohol concentration

BAC is the amount of alcohol in the bloodstream.

BAC’s Affect BehaviorBAC Affect

Feelings of contentment, happiness, relaxationJudgement somewhat impaired.Some loss of coordination.Less able to make rational decisions.Muscle coordination & driving impaired.Loss of consciousness may occur.Breathing may stop (death may result.

0.04%

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0.08%

0.30%

Breath Test

A breath test reflects the alcohol concentration in the pulmonary artery.

One instrument used for breath tests is called The Breathalyzer.

The Breathalyzer is a device for collecting and measuring the alcohol content of alveolar breath.

The BreathalyzerThe Breathalyzer traps 1/40 of 2100 milliliters of alveolar breath.

Since the amount of alcohol in 2100 milliliters of breath approximates the amount of alcohol in 1 milliliter of blood.

The Breathalyzer in essence measures the alcohol concentration present in 1/40 of a milliliter of blood.

Breath TestInfrared-Breath TestUses the principle that infrared light is absorbed when shined on alcohol.

The infrared light passes through a chamber where it will interact with the alcohol and cause the light density to decrease.

The decrease in light intensity is proportional to the concentration of alcohol present in the captured breath.

Breath TestFuel Cell Breath TestA fuel cell converts a fuel and an oxidant into an electrical current. In this test, the breath alcohol is the fuel and atmospheric oxygen acts as the oxidant. Alcohol is converted, generating a current that is proportional to the quantity of alcohol present in the breath.

Field Sobriety Testing It is a set of three tests administered and evaluated in a standardized manner.

Horizontal Gaze Nystagmus (HGN)

Walk-and-Turn (WAT)

One-Leg Stand (OLS)

These tests are administered systematically and are evaluated according to measured responses of the suspect.

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Developed by the National Highway Traffic and Safety Administration

Field Sobriety TestingHorizontal Gaze Nystagmus (HGN)

To identify possible drunk drivers. Research has proven that this test is the most accurate of the three, with a 77% accuracy rating in detecting blood alcohol content level

Nystagmus is the technical term for involuntary jerking or bouncing of the eyeball. A horizontal gaze nystagmus is a lateral or horizontal jerking movement when a person looks toward the side.

Walk-and-Turn (WAT)

It is 68% accurate in identifying blood alcohol content level.

Is a simple, quick test consisting of two parts-

The officer asks the subject to place one foot in front of the other in a straight line with the heel of one foot touching the toes of the other.

The officer instructs the driver to take nine heel-to-toe steps down the line. After the nine steps are taken, the driver must turn around, taking a series of small steps, and return to where he or she started by taking another nine heel-to-toe steps.

Field Sobriety Testing

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Field Sobriety TestingWalk-and-Turn (WAT)During the walk, the subject is to keep his or her hands at the side, watch the feet at all times, and count each step aloud. The driver is not supposed to stop at any point until the test is completed.

One-Leg Stand (OLS)

Field Sobriety Testing

This test is 65% accurate in determining if a driver has a blood alcohol content level.

The subject is instructed to stand with feet together and arms down at the sides.

The subject to continue to keep his or her hands at the sides and raise either leg roughly six inches above the ground. In this position, the subject is asked to count upwards starting at 1,000. 

The one-leg stand test must be performed on dry, hard, level land.

Field Sobriety TestingOne-Leg Stand (OLS)While the subject performs the test, the officer looks for four signs that indicate the person may be intoxicated:

Swaying while balancing.

Using the arms to keep balance.

Hopping on the anchor foot in order to maintain balance.

Resting the raised foot on the ground three or more times during the required thirty seconds.

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Analytical techniques

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analysis of alcohol

Estimation of Ethyl Alcohol in blood and urine

Gas chromatographic technique a. Isolation from blood • 1ml of blood is diluted with 4 ml of water .• It is acidified with few drops of 5% tartaric acid

solution and then distilled .• The distillate (5ml) is collected and an aliquot

of it is injected in to the gas chromatograph .

b. Isolation from urine • 1ml of urine is taken into a micro centrifuge

tube .• Centrifuge it for 15 minutes • 5 micro litre of the supernatent liquid is

injected in to the gas chromatograph .

1. ETHYL ALCOHOL

• CHEMICAL TEST :

DICHROMATE TEST

IODOFORM TEST

ESTER TEST

DICHROMATE TEST

• 1 ml of distillate is added to 0.2ml of 2% potassium dichromate solution.

• Then add 1 ml of conc. sulphuric acid .

• The yellow colour of dichromate changes to green or blue .

• Sensitivity = 2 mg of alcohol .

IODOFORM TEST

• 1ml of distillate in a test tube is added with few drops of 10 % sodium hydroxide followed by drop wise addition of iodine solution till the solution becomes brown .

• The contents are then warmed on a low flame.• Few drops of sodium hydroxide solution are

added to change the colour of the solution from brown to yellow

• If after warming the solution becomes colourless few drops of iodine solution are added.

• The tube is kept over night and precipitate is observed under microscope .

• Characteristic hexagonal crystals of iodoform are seen

• Acetone , aldehyde and armyl alcohol if present will also give this test .

• Sensitivity = 2 mg alcohol .

Ester Test

• 0.5 ml of distillate is added to 0.5 gm of sodium acetate and 1ml of sulphuric acid and warmed on a low flame and finally cooled.

• 5ml of sodium carbonate solution is then added and again cooled

• Fruity odour of ethyl acetate is observed

2. METHYL ALCOHOL

• CHEMICAL TEST :

SCHIFFS REAGENT TEST

CHROMOTROPIC ACID TEST

SCHIFFS REAGENT TEST

• 4.5ml of distillate is added 0.5ml of ethyl alcohol ( if the concentration of ethyl alcohol is already high in the distillate the liquid is fortified accordingly so that 5 ml should contain only 0.5ml ethyl alcohol )

• To it is added 2 ml of 3% KMnO₄ solution and 0.2 ml of phosphoric acid , keep it for 10 minutes

• Then 1ml of 10% oxalic acid is added followed by 1 ml of conc. H₂SO₄ and then contents are cooled at room temperature .

• Then 5 ml of schiffs reagent is added to it and the colour is noticed after 30 minutes .

• Purple colour is observed .• A positive control with 0.5 ml of solution (0.5 %

solution of methyl alcohol is in rectified spirit ) mixed with 4.5 ml of distilled water ,and a black control with 5 ml of distilled water are performed side by side.

• The colour developed in the sample is matched with that of the controlled sample (equivalent to 2mg of methyl alcohol ) , and quantitative estimation is made

CHROMOTROPIC ACID TEST

a. Tissues and stomach wash : • 0.5 ml of the distillate in a hard glass tube is added 0.2

ml of 5% phosphoric acid followed by 0.2 ml of potassium permagnate solution .

• After 5 mins saturated solution of sodium bisulphite is added drop by drop until the permagnate colour is discharged .

• If a brownish colour still persists a drop of phosphoric acid is again added to it and then a drop of sodium bisulphite solution .

• To this colourless solution is then added 5ml of freshly prepared chromotropic acid solution ( prepared by dissolving 50 mg of sodium salt of chromotropic acid into 100 ml of conc. sulphuric acid and then heated in a hot water bath at 60⁰ C for 30 mins , then cooled.)

• A violet colour is obtained ( the final volume of the solution is 6 ml )

• The final solution is taken into the cell of a spectrophotometer and the absorbance is read at 570 nm wavelength .

b. MeOH in blood :

• 0.5 ml of blood is diluted with 4 ml of water and to it is then added 0.5 ml of trichloracetic acid and 0.5 ml of conc. sulphuric acid .

• Shake and then filtered .• 0.5 ml of the clear filtrate is tested instead of 0.5 ml

of the distillate .

Case StudySneha Rasal (37) and her husband Santosh (40) were returning to their Lalbaug residence with three friends, after celebrating the New Year at Bandra, when their WagonR was hit by a speeding Mercedes at around 12.30am. police arrested a drunk Shashikant Bhosale (39), the driver of the Mercedes, from the spot. DCP (zone III) Vinayak Deshmukh said the incident occurred as Bhosale lost control of the Mercedes after entering the wrong lane and brushed the right side of the other vehicle. The remaining occupants of the WagonR suffered minor injuries. Bhosale was booked under sections of the IPC sections 279 (rash driving), 337 & 338 (grievous hurt and act endangering life or personal safety of others)and the Motor Vehicle Act for drunk driving. He was later released on bail. However, he claimed he was not at fault and it was the WagonR which brushed his vehicle at high speed. A Worli cop said Bhosale's blood samples were sent to the Forensic Science Laboratory, Kalina, to ascertain how much alcohol he had consumed.  "The FSL report will take a few months," he said.

Case StudyThe Arrest of Duncan Smith

Duncan Smith was driving home after meeting up with a friend for some drinks to celebrate the end of another week. He only had two beers, but wasn't a particularly large man and hadn't eaten lately, and the effect was noticeable on him. Still, feeling confident that two beers wouldn't incapacitate him, he said goodnight to his friend and drove home. On the way home, his cell phone slid out of his pocket and under the seat. He glanced down to see where it had fallen and by the time he looked up it was too late; his car jumped the curb and smashed into a fire hydrant.Duncan had been driving at a relatively low speed and he was able to walk away from the crash. As he got out of his car to survey the damage, a police officer showed up .

Case StudyThe Arrest of Duncan Smith

Suspecting alcohol, the officer gave Duncan field sobriety tests, making him recite the alphabet, stand on one leg, and try to touch his nose with one finger. The officer shined a flashlight in Duncan's eyes, making him look left and right, and saw that his eyes were red and watery. Even though Duncan passed the sobriety tests, because he had hit a tree and his eyes were red and watery, the officer placed him under arrest and took him to the station to get a blood test. The test showed that Duncan's blood alcohol content was .09, just above the legal limit of .08