Lead poisoning

sources of lead. Types of poisoning, who will be effected,normal values of lead, clinical features, patho-physiology, diagnosis and treatment.

1. LEAD POISONING Dr. Sravani Assistant Professor

2. Introduction to lead What is lead poisoning Sources of exposure Classification of lead poisoning Who is at risk Pathophysiology Harmful effect of lead Signs and symptoms Diagnosis and Treatment Prevention conclusion Contents

3. More industrial workers are exposed to lead than to any other toxic metal. Lead is widely used in a variety of industries because of its properties: Low boiling point Mixes with other metals easily to form alloys Easily oxidised anticorrosive

4. All lead compounds are toxic: Lead arsenate Lead oxide Lead carbonate Lead sulphide is the least toxic. Most dangerous

5. Lead poisoning is a medical condition caused by increased levels of the heavy metal lead in the body, and this can interfere with a variety of body processes and causes toxicity to many organs and tissues. It’s also called plumbism , colica Pictonum or saturnism .

6. Sources

7. Industrial Uses: Over 200 industries are counted where lead is used. Manufacture of batteries, glass , ship building, printing, potteries rubber industry and several others.

8. Occupational exposure : is the main cause of lead poisoning in adults, as in lead miners and smelters, plumbers glass manufacturers, construction workers …etc. Paints: is the main cause of lead Poisoning in children. Many of the children display pica, so even a small amount of a lead-containing product can contain hundreds of milligrams of lead.

9. Soil: is the main cause of lead poisoning in the agricultural areas. By eating food grown in contaminated soil. Water: Lead from the soil or atmosphere can end up in surface water and groundwater. It is also potentially dangerous to be present in drinking water.

10. Lead containing products: Like plastic toys, bottles, cans……etc.

11. Hunting : Animals which are hunted are at high risk of exposure because of the bullets which may contain lead. Breast feeding is also considered as an important route of lead exposure because of the presence of the lead in the affected female milk.

12. Non- Occupational Sources: Greatest source – Gasoline. Thousands of tons of lead every year is exhausted from automobiles.

13. Depends on:- 1- The amount of lead in the blood and tissues. 2- The time of exposure. Lead poisoning may be acute (from intense exposure of short duration) or chronic (from repeat low-level exposure over a prolonged period).

14. Classification Acute poisoning:- In acute poisoning, typical neurological signs are pain, muscle weakness. Gastrointestinal problems, such as diarrhoea, poor appetite, or weight loss. Absorption of large amounts of lead over a short time can cause shock, Hemolysis . Damage to kidneys can cause changes in urination such as decreased urine output.

15. Classification Chronic poisoning :- usually presents with symptoms affecting multiple systems, but is associated with three main types of symptoms: gastrointestinal, neuromuscular, and neurological. Signs of chronic exposure include loss of short-term memory, depression, nausea, abdominal pain, loss of coordination, and numbness and tingling in the extremities.

16. Who is at risk All children under the age of 6 years old. People living in old houses are at great risk . People working in industries. Pregnant woman & developing baby.

17. Normal levels of lead?? Body stores avg in Adults : 150 to 400mg B lood: avg. 25 mcg/100ml Increase to 70mcg/100ml – clinical symptoms. Normally, 0.2 – 0.3 mg largerly from food and beverages. Children: Less than 10 micrograms/ dL of lead in the blood

18. Mode of Absorption INHALATIONAL: Most cases of industrial lead poisoning is due to inhalstional of fumes and dust of lead or its compounds.

19. Mode of Absorption INGESTION: Is of less common occurrence Small quantities of lead trapped in the Upper respiratory tract may be ingested. Lead may also be ingested in food or drink through contaminated hands.

20. Mode of Absorption SKIN Absorption through skin occurs only in respect of the organic compounds of lead. Tetraethyl lead. Inorganic compounds are not absorbed through skin.

21. Mode of Absorption The main body compartments that store lead are the blood, soft tissues, and bone; the half-life of lead in these tissues is measured in weeks for blood, months for soft tissues, and years for bone. Lead in the bones, teeth, hair and nails is bound tightly and not available to other tissues, and is generally thought not to be harmful.

22. In adults, 94% of absorbed lead is deposited in the bones and teeth. In children only store 70% in this manner, a fact which may partially account for the more serious health effects on children.. Many other tissues store lead are the brain, spleen, kidneys, liver, and lungs. It is removed from the body very slowly, mainly through urine. Smaller amounts of lead are also eliminated through the feces , hair, nails, and sweat.

23. Distribution of lead:- 95% of ingested lead is excreted in faeces. Lead absorbed from gut enters the circulation 95% enters erythrocytes. Transported to liver and kidneys finally to bones Released during osteolysis ( during bone resorption ) to soft tissues. 4% brain, liver, kidneys. 1% blood. Crosses placenta, foetal BBB is open

24. It probably exerts its toxic action – by combining wit SH groups of certain enzymes. Ex: Porphyrin synthesis and carbohydrate metabolism. Also effects membrane permeability and potassium leakage from erythrocytes exposed to lead.

25. Harmful effect of lead:- 1- Lead also interferes with DNA transcription, enzymes that help in the synthesis of vitamin D, and enzymes that maintain the integrity of the cell membrane. 2- Lead interferes with metabolism of bones and teeth. 3- Lead alters the permeability of blood vessels and collagen synthesis 4- Lead may also be harmful to the developing immune system, causing production of excessive inflammatory proteins.

26. 5- Lead exposure has also been associated with a decrease in activity of immune cells such as PMN leukocytes. 6- Lead also interferes with the normal metabolism of calcium in cells and causes it to build up within them. 7- Lead also inhibits the enzyme ferrochelatase , and in turn inhibits RBC synthesis and leads to anemia . 8- Lead interferes with the release of neurotransmitters, glutamate, a neurotransmitter important in many functions including learning.

27. Signs and symptoms Lead poisoning can cause a variety of symptoms and signs which vary depending on the individual and the duration of lead exposure. Symptoms from exposure to organic lead, which is probably more toxic than inorganic lead

28. Inorganic lead Abdominal colic Obstinate constipation Loss of appetite Blue line on the gums Stippling of red cells Anaemia Wrist drop Foot drop

29. Renal system: The toxic effect of lead causes nephropathy and may cause Fanconi syndrome. Cardiovascular system: Evidence suggests lead exposure is associated with high blood pressure, coronary heart disease, heart rate variability, and death from stroke. Reproductive system: Lead affects both the male and female reproductive systems. In men, when blood lead levels exceed 40 μg / dL , sperm count is reduced and changes occur in volume of sperm, their motility, and their morphology.

30. Organic Lead compounds mostly effect on CNS

31. Diagnosis History: lead exposure Clinical features : Loss of appetite , Persistant headache,Abdominal cramps,Vomiting ,Weight loss, Constipation, Anemia , Irritability, Learning disabilities,Joint or muscular pains, blue lines on gums, Behavior problems. ( In children-hearing loss, delayed growth, drowsiness, clumsiness, or loss of new abilities, especially speech skills)

32. Laboratory tests : CPU- useful ścreening test (< 150 mcg/ lt - in unexposed) Amino levulinic acid in urine (ALAU): >5mg/ lt Lead in blood and urine: In urine : over 0.8 mg/ lt In blood : 70 mcg/100ml Basophilic stipling of RBC- sensitive parameter.

33. Preventive Measures 1- Substitution : where possible lead compounds to be substituted by less toxic materials 2- Isolation : all processes which give rise to harmful concentration of lead dust or fumes should be enclosed and segregated. 3-Local exhaust ventilation: adequate ventilation to remove fumes and dust.

34. Preventive Measures 4- Personal protection: workers should be protected by approved respirators 5 - Good house keeping: essential where lead dust is present. Floors, benches, machines should be kept clean wet sweeping.

35. Preventive Measures 6- Working atmosphere: 2mg per 10 cu. metres of air. 7- Periodic examinatioin of workers 8 - Personal hygiene 9- Health education

36. Management Treatment for lead poisoning begins with removing the sources of lead and providing balanced nutrition. Saline purge will remove unabsorbed lead from the gut. The use of d- penicillamine has been reported to be effective. CHELATION THERAPY Chelating agents like Ca -EDTA. L ead levels greater than 45 mcg/ dL of blood - E thylenediamine tetraacetic acid (EDTA). Lead poisoning is notifiable and compensatable disease.

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