2013 MBBS BATCH
PREVENTIVE MEDICINE PROF. II EXAM REVIEW 2015
REVISED BY ::
BHAGATH M S
RAJEEV BISWAS
ENVIRONMENTAL HEALTH BIOMAGNIFICATION
1. BIOMAGNIFICATION • •
BIOMAGNIFICATION occurs when a higher level predator eats a lower level organism and ingests the substance with it Even though the level at the lower levels of the food chain (often referred as trophic levels) may have very low concentrations, as moving up the food chain the concentrations become higher and higher
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AIR
LONDON SMOG (SMOG/SO2) CRITERIA AIR POLLUTANT (O3) COMMON SYMPTOMS OF LEAD POISONING COMMON TREATMENT FOR LEAD POISONING GENETIC METHODS FOR OUT-DOOR AIR POLLUTION CONTROL
1. LONDON SMOG (SMOG/SO2) •
5th of December 1952 the London o sky was clear, the weather was considerably colder than usual. o As a result people were burning large amounts of coal. The winds were light and the air near the ground was moist, conditions ideal for formation of radiation fog. During the day of 5th December the fog was not particularly dense, it possessed a dry smoky character, however when nightfall came the fog thickened and visibility dropped to a few meters.
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2. CRITERIA AIR POLLUTANT (O3) •
Ozone: ground level O3 – primary constituent of urban smog – reaction of VOC + NOx in presence of heat +sun light
3. COMMON SYMPTOMS OF LEAD POISONING The common symptoms of Lead poisoning are :: • Abdominal pain • Attention problems • Constipation • Developmental delays or losses • Headache • Irritability or aggressiveness • Poor appetite • School or learning problems • Sensory losses • Sleep disturbances • Sleepiness • Slow growth
4. COMMON TREATMENT FOR LEAD POISONING The common treatment for lead poisoning are :: • Admittance to a critical care unit for severe toxicity • Bowel irrigation to wash lead particles out of the gut 2|Page
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Chelation therapy to bind and remove lead from the body (EDTA) Education regarding lead exposure Extended follow-up to observe for ongoing exposures and to manage complications Gastric lavage to remove lead particles from the stomach Prevention of further exposure Treatment of symptoms as needed Nutrition (milk, egg, Vc)
5. GENETIC METHODS FOR OUT-DOOR AIR POLLUTION CONTROL Genetic methods for out-door pollution control are :: • Atmospheric dilution: restricted • Substitution or limitation: either eliminating it or do not produce it • Reduction in quantity produced and/or released: improve the combustion efficiency, etc. • Process or equipment change: enclosed systems for processes that generate vapors • Air-cleaning technologies • Administrative, economic, and regulatory approaches
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WATER
EUTROPHICATION TREATMENT & PREVENTION OF FLUOROSIS SYMPTOM OF ARSENIC POISONING MUNICIPAL WATER TREATMENT HOCl and OCl- is defined as free available chlorine In drinking water 1 mg/L of chlorine for 30 minutes is generally sufficient to reduce bacterial numbers. Methylmercury and Minamata disease
1. EUTROPHICATION • • • •
Discharge of excess nutrients into lakes and coastal waters Detergents, fertilizers, human and animal wastes Lake becomes biologically more productive Flourishing blooms of toxic blue-green algae
2. TREATMENT & PREVENTION OF FLUOROSIS • •
•
Fluorosis is permanent, it can not be reversed Treatment of Fluorosis involves first remove the source of the problem – drinking water de-fluoride – Switch from surface to groundwater sources – person’s diet have to be changed No other treatments are really available
3. SYMPTOM OF ARSENIC POISONING The symptoms of Arsenic poisoning are :: o Weakness o Headache o Burning of the eyes o Nausea o Diarrhoea
4. MUNICIPAL WATER TREATMENT Municipal treatment including the following steps :: 1. Water source 2. Settlement/ sedimentation 3. Filtration 4. Disinfection (chemical treatment)
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5. HOCl and OCl- is defined as free available chlorine. 6. In drinking water 1 mg/L of chlorine for 30 minutes is generally sufficient to reduce bacterial numbers. 7. Methylmercury and Minamata disease • • •
In 1955 in the Minamata Bay area of Kyushu, Japan caused by the release of mercury in the industrial wastewater from the Chisso Corporation’s chemical factory, which continued from 1932 to 1968. This highly toxic chemical bioaccumulated in shellfish and fish in Minamata Bay
Symptoms • Numbness in the limbs, difficulty in moving the hands and legs, a narrowed visual field, language disorders, difficulty in hearing, disorders of the sense of equilibrium, hand and leg tremors, and movement disorders of the eyeballs • In severe cases, people could become mad or unconscious, leading to death.
Congenital Minamata Disease • Children was born after the initial outbreak, never been fed contaminated fish • Infants were diagnosed with cerebral palsy • Their mothers had contaminated fish • placenta removes methylmercury from the mother's bloodstream and concentrates the chemical in the fetus.
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ENDEMIC DISEASE & SOIL POLLUTION
The single most common cause of preventable mental retardation & brain damage in the world. Goiter Cretinism Treatment and prevention Waste Disposal Landfill
1. The single most common cause of preventable mental retardation & brain damage in the world. IRON DEFICIENCY 2. Treatment and prevention a. Goiter b. Cretinism
TREATMENT • Medical Care • Patients do not routinely require specific therapy unless the goiter is large enough to cause compressive symptoms (eg, tracheal obstruction, thoracic inlet occlusion, hoarseness). • In an adult, 150 mcg/d is sufficient for normal thyroid function. • Surgical Care • Thyroidectomy may be indicated for patients with compressive symptoms of a large goiter PREVENTION • Iodine deficiency is the single most common cause of preventable mental retardation and brain damage in the world • Iodized salt • Cost US$ 0.05 per person per year • Globally, UNICEF estimates that 66% of households now have access to iodized salt. 3. Waste Disposal
Landfills – Must not be built on a floodplain, in areas subject to landslides, mudslide, located near airports – Avoid contaminating groundwater – Waste must be covered daily with dirt to prevent the spread of disease by rats, flies, mosquitoes, birds and other animals – Monitoring systems to detect groundwater contamination 4. Landfill
o Must not be built on a floodplain, in areas subject to landslides, mudslide, located near airports o Avoid contaminating groundwater o Waste must be covered daily with dirt to prevent the spread of disease by rats, flies, mosquitoes, birds and other animals o Monitoring systems to detect groundwater contamination 6|Page
PESTICIDES Indoor residual spraying of DDT Why Organophosphates neurotoxic International Program on Chemical Safety (IPCS, 2002) “An exogenous substance or mixture that alters the function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, or its progeny or (sub)populations” "POPs (persistent organic pollutants) are chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of living organisms and are toxic to humans and wildlife. POPs circulate globally and can cause damage wherever they travel." TCDD dioxin incomplete combustion 1. indoor residual spraying of DDT Why • DDT is cheap and effective. • Behavioral characteristics of the Anopheles mosquitoes— – They bite people indoors at night and the added weight of the blood meal makes it difficult for them to fly, they immediately fly to a nearby wall to rest and excrete the excess fluid from their bodies. – If the wall has previously been sprayed with DDT, it will be absorbed into their waxy body coating, they will be killed, and the transmission cycle will be interrupted.
2. Organophosphates neurotoxic • • • • • • • • •
Was used as war gas in WWII (Sarin ). With acute toxicity, but with relatively minor effects on the environment (no bioaccumulation). For this reason, organophosphates gradually replaced organochlorines. Parathion, 1st synthesized in 1944. Malathion. less toxic to parathion, gradually replaced parathion OPs were first recognised in 1854, but their general toxicity was not established until the 1930s. Tetraethyl pyrophosphate (TEPP) was the first OP insecticide, which was developed in Germany during WWII as a nerve gas. So is sarin. the most acutely toxic of all pesticides to vertebrate animals. unstable and therefore break down relatively quickly in the environment. OPs are nerve poisons which kill the target pest (usually insects).
3. International Program on Chemical Safety (IPCS, 2002) “An exogenous substance or mixture that alters the function(s) of the endocrine system and consequently causes adverse health effects in an intact organism, or its progeny or (sub)populations” 7|Page
4. "POPs (persistent organic pollutants) are chemicals that remain intact in the environment for long periods, become widely distributed geographically, accumulate in the fatty tissue of living organisms and are toxic to humans and wildlife. POPs circulate globally and can cause damage wherever they travel." 5. TCDD dioxin incomplete combustion Cl
O
Cl
Cl
O
Cl
2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) • • • • • • • • • • • • •
The “discovery” of TCDD in the late 1960’s in the Agent Orange (2, 4,5-T) Frequently referred to, inaccurately, as dioxin. July 10th, 1976, an explosion release large amount of TCDD containing material in Seveso, Italy 1970’s, Love Canal in Niagara, NY, USA was discovered with TCDD contamination in the ground water, and lead to the evacuation of the town. Poland and Knutsen discovered the Ah receptor by using TCDD as a ligand; consequently, revolutionize the study of toxicology The most toxic man-made chemical. LD50: 0.6 mg/kg in GP 10,000x higher in hamster The mechanism of death is not known. No toxic effect on cell culture Potent AhR inducer Rodent carcinogen Accidental poisoning in human, chlorlacne, porphyria, immune suppression, etc. By product of the Agent Orange (2,4-D + 2,4,5-T)
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PREVENTIVE MEDICINE QUESTION PAPER 2015 30 JUNE 2015
MCQS (2 MARKS EACH) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10.
WHEAT LYSINE DISACCHARIDES –-> LACTOSE DEFICIENCY OF OCULAR AND EXTRA OCULAR MANIFESTATION DUE TO WHICH VITAMIN RETINOL ACTIVE FORM OF THIAMINE TTP DEFICIENCY OF VITAMIN D IN CHILDREN RICKETS ACTIVATION OF RIBOFLAVIN FAD CHRONIC LEAD POISONING SKIN CANCER FREE FORM OF CHLORINE HOCl CRETINISM IODINE DEFICIENCY WHICH ONE DOES NOT BELONG TO OZONE O2
LONG QUESTIONS (10 MARKS EACH) 1. 2. 3. 4. 5. 6. 7. 8.
SUPPLIMENTARY ACTION OF PROTEIN FUNCTIONS OF CALCIUM FUNCTIONS OF ASCORBIC ACID DEFICIENCY OF NIACIN FOOD POISONING GENERIC FACTORS FOR OUTDOOR POPULUTION CONTROL ARCENIC POISONING - SYMPTOMS MUNICIPAL WATER TREATMENT
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