II CHEMICAL EXPOSURE A.-Solids e.g.: dust, fumes, smoke, smog. A.-Solids e.g.: dust, fumes, smoke, smog. B.-Liquids and vapors including mists and fogs. B.-Liquids and vapors including mists and fogs. C.-Gases. C.-Gases.

Dusts are particular matter in a state of minute division arising from processes like grinding, crushing, blasting and drilling. Dusts are particular matter in a state of minute division arising from processes like grinding, crushing, blasting and drilling. Dusts are classified according to their physical nature or according to their effect on the body. Dusts are classified according to their physical nature or according to their effect on the body. Organic dusts Plant origin such as ….. Animal origin……… Organic dusts Plant origin such as ….. Animal origin……… Inorganic dusts such as…….. Inorganic dusts such as……..

Lead Poisoning Sources: Sources: Battery industry. Battery industry. Plumbing Plumbing Pipe sheets Pipe sheets Paints Paints Printing Printing Petroleum industry as tetraethyl lead (TEL) or organic Lead. Petroleum industry as tetraethyl lead (TEL) or organic Lead.

Routes of absorption 1.-Through the lung:Lead fumes and dust can be absorbed nearly completely if inhaled through respiratory tract. 1.-Through the lung:Lead fumes and dust can be absorbed nearly completely if inhaled through respiratory tract. 2.-Through digestive tract: Only 10% reaches the blood and tissues via this route. The rest are excreted through feces and some are absorbed through portal circulation to the liver to be excreted again with bile into the gastro- intestinal tract. 2.-Through digestive tract: Only 10% reaches the blood and tissues via this route. The rest are excreted through feces and some are absorbed through portal circulation to the liver to be excreted again with bile into the gastro- intestinal tract.

3.-Through skin: 3.-Through skin: Organic lead can penetrate the unbroken and normal skin rapidly to enter the body Organic lead can penetrate the unbroken and normal skin rapidly to enter the body

Clinical symptoms & signs Gastro-intestinal tract : Gastro-intestinal tract : Loss of appetite particularly in the morning Loss of appetite particularly in the morning Metallic taste in the mouth. Metallic taste in the mouth. Constipation is the rule, particularly before attacks of colic. Constipation is the rule, particularly before attacks of colic. Lead line: Occurs in the gums and buccal mucosa and consists of minute particles of lead sulfide due to union between lead in blood and hydrogen sulfide formed by fermentation of food in the teeth pockets. Lead line: Occurs in the gums and buccal mucosa and consists of minute particles of lead sulfide due to union between lead in blood and hydrogen sulfide formed by fermentation of food in the teeth pockets.

2:Lead colic: It occurs in approximately 80% of cases and it may be severe to stimulate acute appendicitis. A very important point in differential diagnosis is that relief is often obtained by making firm pressure upon the abdomen..

Pulse rate drops to 40 –50 per minute. Pulse is small and hard. Pulse rate drops to 40 –50 per minute. Pulse is small and hard. Temperature usually subnormal but during the paroxysm blood pressure is usually elevated Temperature usually subnormal but during the paroxysm blood pressure is usually elevated

Neuromuscular System Neuromuscular System There is tendency towards localization of lead palsy in overused and fatigued muscles and that the distribution of paralysis is related to functional groupings of muscles rather than to their nerve supply. Usually the conditions start by a sensation of heaviness in the limbs especially in the morning then proceed to weakness of the affect muscles, which become fatigued readily and prematurely. Usually the conditions start by a sensation of heaviness in the limbs especially in the morning then proceed to weakness of the affect muscles, which become fatigued readily and prematurely.

The paralysis usually begins in the extensor muscles of the fingers, at first in the right hand of the right-handed persons. The condition is almost always bilateral although it may begin at first on one side and appear on the other side after a few days or weeks. Paralysis of hand and foot muscles may result in wrist drop and foot drop, however, this is rare nowadays. The condition is almost always bilateral although it may begin at first on one side and appear on the other side after a few days or weeks. Paralysis of hand and foot muscles may result in wrist drop and foot drop, however, this is rare nowadays.

Joints : arthralgia Joints : arthralgia Genital System :Abortion in pregnant females. Legislation forbidden the employment of women in occupations involving a lead hazard. Genital System :Abortion in pregnant females. Legislation forbidden the employment of women in occupations involving a lead hazard. Urinary System: Protienuria, coproporhynuria and chronic nephritis (lead nephritis) specially among young exposed persons. Urinary System: Protienuria, coproporhynuria and chronic nephritis (lead nephritis) specially among young exposed persons. CirculatorySystem: Moderate hypertension. CirculatorySystem: Moderate hypertension.

Hypochromic anaemia reduction in both HB% and RBCs, size. Hypochromic anaemia reduction in both HB% and RBCs, size. Punctate basophilia:Blue dots are found in the RBCs under Dark Ground illumination. A count of 10,000 or more per million RBCs in any worker is a suggestive evidence to suspend him temporarily from exposure to lead Punctate basophilia:Blue dots are found in the RBCs under Dark Ground illumination. A count of 10,000 or more per million RBCs in any worker is a suggestive evidence to suspend him temporarily from exposure to lead

Investigations –Blood a) hypochromic anaemia a) hypochromic anaemia b) stipped cells: more than 10,000 per million R.B.Cs. b) stipped cells: more than 10,000 per million R.B.Cs. c) lead in blood: more than 80 µg/100 c) lead in blood: more than 80 µg/100

Urine Urine a) Coproporphyrine in urine a) Coproporphyrine in urine b)Al A (Amino levolenic acid) b)Al A (Amino levolenic acid) More accurate and specific than coproporphyrine.

Management 1-Acute poisoning 1-Acute poisoning Calcium gluconate 10 cc. 10% I.V. repeated every 2 hrs until colic is relieved. Calcium gluconate 10 cc. 10% I.V. repeated every 2 hrs until colic is relieved. Nitrites sublingually for colic. Nitrites sublingually for colic. Antispasmodics Antispasmodics Restoratives:-Iron compounds for anemia Restoratives:-Iron compounds for anemia

Calcium Calcium Thyroid extract Thyroid extract Vit B complex & B12. Vit B complex & B12. Purgative enema for constipation Purgative enema for constipation

2-Chronic stage 2-Chronic stage The aim is to remove lead from skeleton to blood in non-ionized form by giving chelating agent. The aim is to remove lead from skeleton to blood in non-ionized form by giving chelating agent. a) Parenteral a) Parenteral Disodium calcium salts of Ethylene Diamine tetra acetic acid (EDTA) Disodium calcium salts of Ethylene Diamine tetra acetic acid (EDTA) b) Oral route b) Oral route Mozatil or penicillamine