Toxicology and Epidemiology PDF

Toxicology- Epidemiology Routes of Entry Inhalation, Ingestion and Absorption, after entering ADME, absorption, distribution, metabolism and excretion Ingestion Through the mouth. When swallowing a substance, the substance enters the digestive...

Toxicology- Epidemiology Routes of Entry Inhalation, Ingestion and Absorption, after entering ADME, absorption, distribution, metabolism and excretion Ingestion Through the mouth. When swallowing a substance, the substance enters the digestive system and ultimately into the bloodstream through the stomach Absorption through the skin and enter the bloodstream and travel throughout the body, when the skin has lacerations or abrasions, accidental injection such as a needle stick Inhalation Air enters the body through the nose or mouth and travels through to the alveoli Tidal volume up to one breath per second and a total intake of up to 120 L. skin consisting Epidermis, Dermis, and hypodermis (fatty layers) Local effects site of the damage is at the point of contact with the substance, for example: a corrosive burn on the skin Systemic effects The site of damage is at a point other than the point of contact, such as a target organ, Target Organ for example: the effect of inhaled lead fumes on the brain. Acute effects Exposure to many occupational hazards causes the body to produce an immediate obvious response, called an acute effect, reversible, such as : nausea, headache Chronic effects substances cause chronic effects, which usually appear a long time after the exposure occurred and persist over time, take 20 or 30 years to develop its often irreversible latency period the period of time between the exposure and the first sign of disease Atopic dermatitis (Eczema) is the tendency of the skin to become inflamed. It is a common condition which tends to run in families Contact Contact with a hazardous substance cause inflammation of the contacted area of the dermatitis skin. This can be caused by either: an irritant – a substance that damages the skin an allergen – a substance that can cause the body to react Highest percentage cause contact dermatitis is synthetic resin manufacturing, petroleum and grease, tanner Immunisation process of giving dead or weakened forms of the disease causing bacteria to a person, usually as an injection, does not cause the disease but the immune system responds and creates antibodies LC50 inhaled concentration sufficient to kill 50 % of a test population in a fixed period of time (usually 4 hours) ml/Kg or mg/L of body weight LD50 Oral or dermal dose which when administered to a test population, is sufficient to kill 50 % of that population. mg/Kg ‘Inhalable dust total dust that will enter the nose and mouth and lungs during breathing Inhalable particulate matter 7 duct diameter, upstream>3 free of any obstruction inserted into the duct system and connected to a manometer. Pitot tubes are used to measure various pressures within the system. Velocities at or below 600–800 fpm. Manometer Used to measure pressure u-shape tube with Hg liquid change in height reading give pressure Rotating Vane Measure airflow through large supply and exhaust systems. It is recommended that the size of the Anemometers rotating vane anemometer should not exceed 5% of the cross-sectional area of the duct. Thermal Heat removed by an air stream as it passes over a probe, which allows for calibration to the velocity of Anemometers the air stream at a given density. should be perpendicular to the air stream and maintained in that position until such time as the measurement is stabilized Blast gates used to balance the airflow in ducts of different sizes Measuring LEV Qualitative : Visual Inspection, Dust Lamp Tyndall Illumination, Smoke Quantitative: Capture Velocity, Face Velocity, Transport Velocity, Static Pressure Smoke tube is titanium tetrachloride Psychosomatic Due to self suggestion, on the job, Psychosomatic response to stress not related to IAQ Syndrome-PS Multiple chemical Person show sensitivity or intolerance to exceptionally low level of commonly used chemicals sensitivity Reynold’s number determine the type of flow pattern of air and fluids, Re is higher than 4000 for piping system, RE Laminar 4000 Calculating partial Partial pressure = concen./106 X 780 if concentration in PPM pressure Sampling Error Large particles---oversampling , sample particle under sampling Isokinetic sampling collects particles in a moving stream which moves at the same velocity in the sampling nozzle as elsewhere in the stream. This can increase the accuracy and reliability of results Baghouses Air pollution control device, capture dust and particulate matter less 0.25miccron, have temperature restriction, due to filter nature (cotton, nylon), filter too dirty it will drop the pressure and affect operation and should be clean by removing dust cake Cyclones Industrial gas Cleaners, collect smaller particles , great 5 mic, no T restriction, low price but high operation cost energy required to overcome the high pressure drops Electrostatic Dust/fume/smoke, charge particle with +ve or –ve charge, charge paltes with opposite precipitator charge, the plate will collect the particles , larger 0.25 , low P and T restriction Efficiency = Mass removed/Mass entered , mass enter 80g , removed 32 g =82-32/82x100, Summary  A sampling pump with an MCE filter is used to collect airborne particulate matter.   A sampling pump with a cyclone is used to collect respirable airborne particulate matter.  A sampling pump with an impactor is also used to collect airborne particulate matter.  A sampling pump with a charcoal tube is used to collect gases and vapors that will adsorb to the charcoal. It is commonly used for a variety of volatile organic compounds VOC.  Ambient aerosal condensation nuclei counter used quantitive fit test method  A PID uses ultraviolet light to ionize molecules in the air. Results are provided in real-time.  A photometer is used to measure particle concentrations in the air. Results are provided in real time.  A denuder is used to measure semi-volatile air concentrations. Results are provided after analysis in the lab.  An impinger is used to measure a variety of airborne contaminants. Results are provided after analysis in the lab.  Water sample after received by the lab shall login and assure chain of custody  Analytical sensitivity is the major factor to determine the required sample volume  CO is sampled by using Ecolyzer, detector tube is used throughout the day to sample from workers breathing zone.  O2 deficiency is measured by galvanic sensing cell, paramagnetic gas analyzer, coulmetric detector  Colormeteric detector that give immediate information regarding the concentration vapors of mixed gases, best use by someone skilled in their use and can not use for TWA and STEL Normal and standard STP: 32F/0C, 14.7 PSI,1 atm and 760 mmHg pressure /Temp NTP: 68 F/20C , 14.7 PSI, 1 atm and 760 mmHg For ideal gas STP the molar volume 22.4L, NTP the molar volume 24.4 L Gay-Lussace P1/T1+460=P2/T2+460 if T in F pressure Temperature Evaluation of Indoor use CO2 as indication of ventilation and adequate/inadequate, typical indoor between dilution ventilation 410-2000 ppm, OSHA PEL: 5000 ppm/8hr, CO2 used as surrogate for others gases, ASHRE not higher than 700 above outdoor, Global 416 ppm Parkinson disease Overexposure of Mn, globus pallidus affect the brain, slow movement ,speech difficulties and fixed stare, such as welding fumes , welders Cryogenic liquids, N Liquid nitrogen, quickly vaporized, resulting O2 deficiency, lead to asphyxiation, frostbit Multi gas meter Used in measuring the gases in the confined space, O2 19.5-23.5, LEL not more 10%, H2S 10 Combustible gas PPM, CO 50 PPM, Methane 25% of space mean , 75% Air , 0.75*20.8(oxygen % in air)=15.5 indicators CGI not acceptable, CO2 4% (40000 PPM) , 9% cause lose of consciousness Hydrazine N2H2 Volatile Alkaline, highly toxic , PPM = conce in mg/m3 /M.W X 106 Indoor pollutant CO2, Tobaco, Radon, NO2, Formaldehyde from wood, Pb , Asbestos, Volatile organic compound VOC, pesticides Indoor air quality Outdoor air samples compared to the indoor samples to determine fungal, bacteria species IAQ, monitor generated, sample points at 3 and 5 feet children and adult simulations Battery charging Lead acid battery produce H gas, at high concentration is explosive room Pesticides Organophosphates: acetylcholinesterase, diarrhea, urination, miosis, bradycardia slow heart rate, vomiting using atropine as antigen to reduce the toxicity Carbamates : acetylcholinesterase less sever and shorter duration Organochlorines: DDT, methoxychlor, dieldrin, chlordane, toxaphene, effect on the nervous system , seizure, tremors or ataxic gait, measure patch on worker cloth Molar Concentration Solute (mole) /Solution (liters), what is molar concentration20 g of ethanol dissolved in 500 ml? mole = weight/M.w 20/46 = 0.43, molar concertation = 0.43/0.5= 0.87 mol/l Gas mixture C1/T1+C2/T2 500 PPM of acetone (TLV 750PPM), 50 ppm MEK (TLV 200ppm) 500/750+50/200 =.9 less than one which is acceptable Vibrio Bacteria, commonly found in seawater. Most infections occur during summer and fall months parahaemolyticus when Vibrio counts in seawater are highest. Most of the time, gastroenteritis follows ingestion of undercooked seafood, especially shellfish. is oxidase positive, facultatively aerobic, and does not form spores, cholera group Mutualism, Mutualism is a symbiotic relationship in which both species benefit. E coli in human commensalism, Commensalism is a symbiotic relationship in which one species benefits while the other parasitism species is not affected. Microscopic mite live on human skin Parasitism is a symbiotic relationship in which one species (the parasite) benefits while the other species (the host) is harmed. Malaria Chemical Hygiene To protect laboratory workers from hazardous chemicals, required to implement a written plan chemical hygiene plan developed by the chemical hygiene officer Handle contaminated sharps objects shouldn’t be hand to hand and should dispose of without contaminated bending or recap, using engineering control, highest incident among medical is after use sharps to predisposal Carburizing Hardening, heat treatment through iron absorption of CO, via heated metal in presence of charcoal/CO, to resist to wear, CO might release through process Employee exposure monitoring or measuring of a toxic substance or harmful physical agent, including records personal, area, grab, wipe, or another form of sampling, as well as related collection and analytical methodologies Biological monitoring results which directly assess the absorption of a toxic substance or harmful physical agent by body systems (e.g., the level of a chemical in the blood, urine, breath, hair, fingernails, etc.) but not including results which assess the biological effect of substance or agent which assess the biological effect of a substance or agent or which assess an employee's use of alcohol or drugs. Meniere's disease Abnormal condition within the labyrinth of the inner ear that can lead to a progressive loss of hearing. The symptoms are dizziness or vertigo, hearing loss, and tinnitus (ringing in the ears). Antibodies A type of protein made by certain white blood cells in response to a foreign substance (antigen). Siderosis Is a lung disease caused by inhalation of FeO or another metallic particle Toxicity The effects of exposure to a substance depend on dose, rate, physical state of the substance, temperature, site of absorption diet and general state of a persons health. Threshold Limit Airborne concentrations of chemical substances and represent conditions under Values (TLVs) which it is believed that nearly all workers may be repeatedly exposed, day after day, over a working lifetime, without adverse health effects. Regulated by NIOSH Permissible Exposure Legal exposure limit concentrations to airborne substances in the United states and are Limits (PEL) established by the Occupational Safety and Health Administration (OSHA). Largely based on the adoption of NIOSH TLVs. Recommended Exposure limit; generally a time-weighted average; developed by NIOSH. Exposure Limit (REL) Physical Hazards Problems caused by such things as noise, temperature extremes, ionizing radiation and pressure extremes are physical stresses. It is important that the employer, supervisor, and those responsible for safety and health be alert to these hazards because of the possible immediate or cumulative effects on the health of employees. Virus A sub-microscopic infectious agent that is unable to grow or reproduce outside a host cell. Examples: common cold (rhinoviruses), AIDS, HIV, Herpes, Hepatitis- B and C. Components: nucleic acid, capsid, envelope, NOT a 'cell wall' Bacteria Single-celled microorganisms can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). Examples:  E. coli, Streptococcus, Tuberculosis. biological safety Class 1 -room air flows through front if cabinet.- 8 inches cabinets - prevent aerosols generates in cabinet from escaping to room.- Not appropriate for experimental systems vulnerable to airborne concentrations. Class 2: Protects worker and research material -Room air - Partial recirculating of HEPARIN-filtered air. – the downward flow hepatitis-filtered air creates contaminant- free zone. class 3: Provides physical barrier between agent and worker. —highest degree of worker protection – Arm-length rubber gloves and sealed front panel. -Air drawn into cabinet through hepatitis filtration Facility design and construction serves as secondary barriers. That is, the primary purpose is to prevent the escape of hazardous materials or agents outside of the controlled environment. The design and construction of a laboratory will depend primarily on the nature and potential hazards of the particular agent. Centrifugal fans Used against low to moderate static pressures such as in heating and air conditioning work. Low space requirements and quite. Axial flow fans: Used against low to moderate static pressures such as in heating and air conditioning work. Low space requirements and quite. Calculating Real Af=(NRR-7)/2 +5 World NRR Attenuation When using and ear plug and muffs. Thoracic Outlet Defined as a disorder resulting from compression of nerves and blood vessels between Syndrome the clavicle and first and second ribs at the brachial plexus caused by typing, keying, carrying heavy loads, or keeping the head, arms, and or shoulders in an unnatural position Design Toggle Switches : Easily seen and reliable in operation. They should preferably have only two positions: "on" and "off." discrete operation Knobs: Without click stops are suitable for fine precise regulation over a wide range Limit Switches: Operated by the motion of a machine part or presence of an object. They are used for controlling machinery as a part of a control system, as a safety interlocks, or to count objects passing a point Push Button: Operated by the pressure of either finger or hand and operate similarly to a switch. Biological Exposure Medical sampling determinants for a persons exposure to occupational and non- Indices (BEI) occupational hazardous chemicals, published by ACGIH. BEI's help to measure an employees' exposure to: occupational benzene, non-occupational benzene, and hazardous gas exposure (NOT Biohazards) The designation "CIH" is awarded by the: ABIA Who accredits industrial hygiene laboratories: AIHA Radon target organ lungs Radium target organ bone for soluble form, GI tract for insoluble form primary reservoir for lead in the body bones Shaver's Disease From exposure to silica and aluminum dust fumes Antigens: foreign substances that trigger the attack of antibodies in the immune response; and found on the surface of microbes. they are either: proteins, polysaccharides, glycoproteins, or nucleoproteins. BSL-1: no special precautions BSL-2: lab coat, gloves, eye protection BSL-3: biosafety cabinets to prevent airborne transmission  BSL-4: sealed, negative pressure Exhaust air is filtered twice Summery 1. Pitot tubes usage is limited to velocities at or below 600–800 fpm. 2. Blast gates are used to balance the airflow in ducts of different sizes. 3. Capture velocity is defined as the minimum velocity of hood-induced air necessary to capture the contaminant. 4. When calculating the static pressure of the hood, remember that the SP is always +ve. 6. Backward curved fan blades are the most efficient. 7. Centrifugal fans are the best for local exhaust ventilation systems. 8. The equation for calculating capture velocities of plain hood openings is only accurate for a limited distance of 1.5 times the diameter of a round duct or the side of a rectangle or square duct. 1. OSHA’s Blood-Borne Pathogen Standard is found in 29 CFR 1910.1030. 2. The etiological agent for anthrax is B. anthracis. 3. Plague is an infectious disease of animals and humans caused by a bacterium named Y. pestis. 4. Tetanus, also known as “lockjaw,” is a disease of the nervous system caused by C. tetani. 5. The bacterium M. tuberculosis causes tuberculosis. 6. Person-to-person transmission through the faecal–oral route is the primary means of HAV in the US. 7. Hepatitis B can be transmitted by percutaneous or mucous membrane exposure to infectious blood or body fluids that contain blood. 8. Aspergillus is a fungus (mold) that can cause aspergillosis in farmers and grain workers. 9. 3 primary preventive measures in biological safety include laboratory practice and techniques, safety equipment, and facility construction and design. 1. Ionizing radiation occurs as the result of particles or electromagnetic waves having enough energy to detach electrons from atoms or molecules, thereby causing ionization of the atom. 2. The 3 types of particle radiation are alpha (α), beta (β), and neutron (n). 3. α radiation is a helium nucleus that has 2 neutrons and 2 protons. 4. β particles are excess electrons. They are formed when an atom with one excess neutron transforms the neutron into a proton and ejects the extra electron. 5. Neutron radiation is indirect ionizing radiation, which consists of free neutrons. 6. The two types of electromagnetic radiation are gamma (γ) radiation and x-rays. 7. Gamma rays are released when an atomic nucleus releases excess energy after a decay reaction. 8. X-rays are produced when an atomic nucleus stabilizes itself by taking an electron from an electron cloud. 9. Biological effects of ionizing radiation are attributed to the ionization process that destroys the capacity for cell reproduction or causes cell mutation. 10. Radioactive decay occurs as alpha decay, beta decay, or series chain. 11. The radiological half-life is the time that it takes for one-half of the atoms of that substance to disintegrate into another nuclear form. 12. The 3 primary controls for radiation are time, distance, and shielding. 13. Reducing the time means less exposure. 14. The dose received by employees is inversely proportional to distance; therefore, the greater the distance from the source means the less the dose. 15. By placing an appropriate shield between the radioactive source and the employee, radiation is attenuated and exposure may be completely eliminated or reduced to an acceptable level. 16. OSHA’s ionizing radiation PEL is 5 rem/year, 1.25 rem/quarter. 2. Each behavior-based safety program has the following elements in common: identify (or target) behaviors that affect safety, define these behaviors precisely enough to measure them reliably, develop and implement mechanisms for measuring those behaviors In order to determine their current status and set reasonable goals, provide feedback, and reinforce progress. 3. Behavior-based safety is not a tool that should be used to blame the workers for their own injuries. 1. Industrial hygiene is the science and art dedicated to the anticipation, recognition, evaluation, and control of workplace hazards that may cause worker injuries and illnesses. 2. The reasons for conducting air sampling are to determine compliance with regulations, to assess worker exposures to determine if PPE is adequate, to monitor implemented control measures, to evaluate contaminant emissions, and to provide documentation. 3. Grab sampling is collecting a known volume of air in a container for laboratory analysis or by a direct-reading instrument. 4. Personal sampling involves an employee wearing an air sampler while he or she performs his or her normal work routine. 5. Area sampling uses the same type of pump and media as in personal sampling, but the sampling device is stationary throughout the sampling period. 6. Integrated sampling involves collecting one or more samples and then combining them to estimate the workers’ 8-h time-weighted average exposure. 7. When analyzing samples, it is highly recommended that you use an AIHA-accredited laboratory. 8. Before sampling, determine whether the contaminant is a gas, vapor, mist, fume, or particulate. High volume and low-pressure drop, commonly used for general ventilation or dilution ventilation work. 9. Filter media are used primarily to sample particulates, such as total and respirable particulates, metals, lead, zinc, and so on. 10. Sorbent tubes are used for sampling gases and vapors. 11. Air sampling pumps and direct-reading instruments must be pre- and post-sample calibrated using a primary standard or a secondary standard traceable to a primary standard. 12. If the post-sampling flow rate is outside the ±5% of the pre-sampling flow rate, samples must be discarded. 14. Limit of quantification is the concentration level above which quantitative results may be obtained with a certain degree of confidence. 15. Target concentration is an estimate of the airborne concentrations of the contaminant being tested. 16. When working in a potentially explosive environment, insure that all sampling equipment is classified by the manufacturer as “intrinsically safe” prior to using. Adult push with 44 pound if coefficient 0.3 , if 0.6 push force 66 pound 1.Aleaking pressurized piping system ejects 5gallons of ethyl alcohol in a laboratory that is 15 feet by 15 feet by 8 feet. The molecular weight of ethyl alcohol is 46, and the SG is 0.79. LEL is 3.3%. With no air change and complete evaporation, does the ethyl alcohol concentration created exceed the LEL? Convert % = 153859/100000 =.153 X 100 = 15 % Vapor from a process tank is generated at 1.2 cfin. The process location room measures 100 feet by 110 feet by 10 feet. Due to a fan malfunction, the dilution ventilation has been reduced to 2000 cfm. Calculate the vapor concentration generated in the room, after the process tank has operated for 5 minutes, 15 minutes, and 25 minutes. An industrial hygienist uses a sound level meter to determine the noise level in the center of 4 identical machines. The reading is 79.55 dB. Based upon this reading, determine the sound level reading of each machine. Lp = Lpi + 10 logN Lpi = Lpj - 10Xlog 4 , Lpi =79.55-6.02 , Lpi = 73.53 dB The test for chromium (VI) is for the "total chromium in the urine to be conducted at the end of shift at end of the workweek." Thoracic outlet syndrome Compression of nerves and blood vessels between clavicle and first and second ribs is a disease ACIH is involved in a monitoring operation using a carbon monoxide direct reading instrument. The instrument has recorded readings of 20 ppm for 4 hours. Abruptly, without any change in plant conditions, the indicator increases rapidly to 75 ppm and has remained constant for 5 minutes. This should initiate what action? The reading of 65 ppm is not life-threatening (the IDLH is 1200 ppm), and recalibration should be able to be accomplished in fresh air in a very short time. A pocket dosimeter measures a person's accumulated radiation dose, A pocket dosimeter is frequently used in conjunction with a film badge (Themoluminescent Dosimetry Badge). RAD Amount of absorbed energy deposited in tissue/matter Roentgen A measure of the energy deposited in tissue/matter Roentgen Equivalent Man (REM) a biologically weighted absorbed dose. Benzene biological monitoring via Urine test after the work shift "the term' containment' is used in describing safe methods, facilities and equipment for managing infectious materials in the laboratory environment where they are being handled or maintained." the best method to prevent infection from a surface in a lab via Containment biosafety levels BSL-1-agents not known to consistently cause disease in healthy adults BSL-2-agents associated with human disease, hazard is from percutaneous injury, ingestion, mucous membrane exposure BSL-3-indigenous or exotic agents with potential for aerosol transmission; disease mayhave serious or lethal consequences BSL-4-dangerous/exotic agents that pose a high risk of life-threatening disease, aerosol-transmitted lab infections, or related agents with unknown risk of transmission The least common form of cold stress is chilblains Kinesiology is the scientific study of human or nonhuman body movement. Kinesiology addresses physiological, biomechanical, and psychological mechanisms of movement Musculoskeletal disorders (MSDs) affect the muscles, nerves, blood vessels, ligaments, and tendons. Workers in many different industries and occupations can be exposed to risk factors at work These disorders have received many names, such as:  Repetitive motion injuries  Repetitive strain injuries  Cumulative trauma disorders  Occupational cervicobrachial disorders  Overuse syndrome  Regional musculoskeletal disorders  Soft tissue disorders Safety margin= minimum strength - maximum strength÷ minimum strength