PCM 2.07 v2 Environmental and Occupational Toxicology PDF

PREVENTIVE AND COMMUNITY MEDICINE I Environmental and Occupational Toxicology Block 2 Edmyr M. Macabulos, MD, MPH | October 22, 2024...

PREVENTIVE AND COMMUNITY MEDICINE I Environmental and Occupational Toxicology Block 2 Edmyr M. Macabulos, MD, MPH | October 22, 2024 Trans 2.07 OVERVIEW biologic material I. History V. Fundamental Rules of A. Definition of Terms Toxicology Toxic substances produced by biologic systems: II. Toxicology VI. Factors Affecting Response to Toxin phytotoxin (plant), zootoxin (animal), and A. Environmental Toxicology Toxic Agents bacteriotoxin (bacteria) B. Occupational Toxicology VII. Exposure Concepts III. Spectrum of Undesired Effects VIII. Common Environmental A. Allergic Reactions Toxicants Any agent capable of causing serious injury to a B. Idiosyncratic Reactions A. Pesticides Poison biological system, resulting in loss of function C. Immediate vs. Delayed B. Metals or death Toxicology C. Solvents and Vapors D. Reversible vs. Irreversible D. Tobacco Smoke Toxic substances produced by or a byproduct of Toxic Effects IX. Individual Practices Toxicant human activities E. Local vs. Systemic X. Hierarchical Control of Toxicity Chemicals IV. Environmental Health XI. Important Things to Overdose of drugs, medicine, chemicals, or Poisoning Paradigm Remember in the Workplace biologic substances A. Interventions and Safeguards Probability that a person will be harmed or experience an adverse effect upon exposure to LEGEND Risk ⭐: Important information a hazard—potential or likelihood that injury will occur LEARNING OBJECTIVES Amount of chemical that is available for Define toxicology and commonly associated terms. Exposure absorption Understand the basic concepts of toxicology and its sub-discipline of environmental and occupational Probability that harm will not occur under toxicology. Safety specified conditions— inverse of risk Discuss the factors affecting responses to toxic agents. Discuss exposure situation to toxic agents. Identify the common types of chemicals and their toxic II. TOXICOLOGY Table 2. Definition of the two types of toxicology effects. Discuss the preventive measures in environmental and Environmental Toxicology Occupational Toxicology occupational toxicology. Study of the impacts of Study of the adverse effects of chemical pollutants in the agents encountered by I. HISTORY environment on non-human workers during the course of Paracelsus (Theophrastus Bombastus von Hohenheim; biological organisms their employment 1493 - 1541) ○ Swiss physician and alchemist ○ ⭐ Father of Modern Toxicology A. Environmental Toxicology Assesses and estimates the fate and effects of toxic ○ “All substances are poisons - there is none which is not substances on the natural environment to include its fauna a poison; the right dose differentiates a poison from a and flora. remedy” Focuses on populations, communities, and ecosystems Non-toxic chemicals (e.g., sugar) can be toxic at high doses B. Occupational Toxicology Highly toxic chemicals can be therapeutic when Silent Spring by Rachel Carson (1962) given in appropriate doses ○ “Can anyone believe it is possible to lay down such a ↪ Ipecac is used as an emergency treatment to barrage of poisons on the surface of the earth without induce vomiting in cases of poisoning. making it unfit for all life?” ○ Raised public awareness about the dangers of A. Definition of Terms pesticides to both the environment and the health of Table 1. Definition of terms animals and humans TERM DEFINITION ○ In humans, pesticide toxins accumulate in fat, where Study of adverse effects of toxic chemical, they remain in the body and can lead to disease and Toxicology physical, and biological agents on living illness. organisms ○ The outcry that followed its publication forced the banning of DDT and spurred revolutionary changes in Person trained to examine the effects of toxic environmental laws. Toxicologist substances—the cellular, biochemical, and Chemicals pollute the environment to such extent that they molecular mechanisms constitute potential hazards to man and animals Toxicity Ability of a substance to cause injury to a Page 1 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO  PCM 2.07 Environmental Toxicology III. SPECTRUM OF UNDESIRED EFFECTS effects are produced The spectrum of undesired effects of chemicals is broad ⭐ : Most substances, except In therapeutics, each drug produces a number of effects, but for highly reactive materials, usually only one effect is associated with the primary produce systemic effects objective of the therapy. Distant sites from point of All the other effects are referred to as Side Effects contact may involve many ○ Some side effects may be desired for another therapeutic organ systems indication EXAMPLES ○ Other side effects of drugs are always deleterious to the Consumption of lead well-being of humans, referred to as Adverse, causing damage to the Deleterious, or Toxic effects of the drug Contact with acid creating a kidneys chemical burn Exposure to hydrogen A. ALLERGIC REACTIONS Ozone exposure causing fluoride causing pulmonary Also referred to as: Hypersensitivity, Allergic reaction, lung irritation edema Sensitization reaction Aldehyde splash in the eyes Exposure to arsine causing Immunologically-mediated adverse reaction to a chemical hemolysis of RBCs resulting from previous sensitization to that chemical or to a structurally similar one ○ ⭐ : Once sensitization has occurred, allergic reactions IV. ENVIRONMENTAL HEALTH PARADIGM may result from exposure to relatively low doses of chemicals B. IDIOSYNCRATIC REACTIONS ⭐: Chemical Idiosyncrasy refers to a genetically- determined abnormal reactivity to a chemical The response observed is equally qualitatively similar to that observed in all individuals ○ May have extreme sensitivity to low doses or extreme insensitivity to high doses of the chemical Figure 1. Environmental health paradigm. C. IMMEDIATE VS DELAYED TOXICITY Table 3. Immediate vs Delayed Toxicity Table 6. Paradigm portions and their descriptions IMMEDIATE DELAYED PORTION DESCRIPTION Occurs after some time upon Occurs rapidly after a single In order for a toxic the administration of the administration of the substance substance to affect substance people, it must come into Table 4. Acute vs Chronic Toxicity contact with them and ACUTE CHRONIC enter the body. Cumulative damage to specific The environmental health Occurs immediately (hours or organ systems after months or paradigm shows how days after exposure) years before having a xenobiotic chemicals, like recognizable clinical disease toxic substances, can be emitted by a polluting EXAMPLES source and move through Skin Absorption: the environment to reach Inhalation: exposure to absorption of phenol people. hydrogen fluoride causing through the skin creating a pulmonary edema chemical burn When contaminants are Inhalation: asbestos Inhalation: formaldehyde released into the causing cancer to the causing irritation to environment, they can lungs mucous membranes enter the air, water or soil (Exposure Pathways) D. REVERSIBLE VS IRREVERSIBLE EFFECTS ○ When >1 is identified, ⭐: If the chemical produces pathological injury to a tissue, they are called Multiple Pathways the ability of the tissue to regenerate determines whether the effect is reversible or irreversible. E. LOCAL VS SYSTEMIC TOXICITY All these pathways can Table 5. Local vs Systemic Toxicity contaminate food sources LOCAL SYSTEMIC ⭐: Occur at the site of Require absorption and and affect the flora and fauna of ecosystems. contact between the dissolution of toxicant from biological system and the its entry point to a distant toxicant site at which its adverse Page 2 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO  PCM 2.07 Environmental Toxicology Contaminants can only affect health when they enter the body through an entry route, and this can happen through multiple entry routes (shown in Table 7) Even if contaminants come in contact with people, they may not cause adverse effects due to individual susceptibility Figure 2. Factors affecting responses to toxic agents. to agents, which varies between groups of people Table 8. Response-affecting factors and their examples (depending on genetics, FACTORS EXAMPLES general health, etc.). ⭐ Less susceptible = More Chemical & Physical Properties Physical state, solubility, reactivity, vapor pressure resistant to chemical toxicity Age, sex, nutritional status, Individual Factors genetic background, general Table 7. Typical entry routes for contaminants health status of the individual ENTRY ROUTE DEFINITION Duration, frequency, route, Exposure Situation Inhalation Intake via lungs by breathing dosage Absorption Passage through skin Ingestion Entry through mouth VII. EXPOSURE CONCEPTS Accidental needle sticks by Different toxic responses may rise from different: Injection ○ Routes of exposure health care professionals ○ Frequencies of exposure ○ Duration of exposure (acute vs chronic) If the contaminants do NOT ENTER the environmental compartments (air, water, or soil) or the body, then they ⭐ Risk = (Toxicity) x (Exposure) will NOT cause adverse health effects. ○ Risk - potential or likelihood that injury or biological If a person is NOT SUSCEPTIBLE to the contaminant, damage will occur in a given situation disease will not occur. ○ Toxicity - ability of a substance to cause injury to To prevent harm from contaminants, controls may be biologic material established at key points along the paradigm. ○ Exposure - amount of chemical available for absorption ○ E.g., pollution can be avoided by using nontoxic Occurrence of Toxic Effects: substances at the source ○ Toxic outcomes typically arise unintentionally If the source does not produce toxic contaminants, Intentional ingestion they can be contained, recycled, or modified so that Occupational contact pollutants do not enter the environment. Environmental exposure Not all exposures lead to toxic manifestations due to a V. FUNDAMENTAL RULES OF TOXICOLOGY number of factors: Exposure must occur for a chemical to present a risk. ○ Sufficient concentration of the chemical agent or a Magnitude of risk is proportional to both the potency of the metabolite must need to persist at an organ or tissue chemical and the extent of exposure. where the toxic effect is elicited “The dose makes the poison” ○ Importance of not just the exposure itself but the ○ Toxicity depends on the amount of chemical at the specific conditions required for toxicity to manifest, target site. providing insights for preventive measures [Batch 2028] ○ Toxic effects in a biological system are NOT produced by ○ Each of these factors influence the magnitude of the a chemical agent. dose received They occur only when the chemical or its metabolic breakdown or biotransformation products reach the A. TOXIC AGENT CLASSIFICATION Table 9. Toxic Agent Classification appropriate site in the body at a sufficient SOURCE COMMENT concentration and duration to produce a toxic manifestation. Target Organ Liver, kidney, lungs Industrial solvent, pesticide, Use VI. FACTORS AFFECTING RESPONSE TO TOXIC AGENTS food additive Source Plant and animal agents Toxic response depends on the chemical and physical Carcinogen, teratogen properties of the agent, the exposure situation, how the Effect (increased risk for birth agent is metabolized, and the overall susceptibility of the defects), liver damage biological system or subject. Physical State Solid, liquid, gas, particulates Chemical Stability or Reactivity – General Chemical Structure Aromatic amine, halogenated Page 3 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO  PCM 2.07 Environmental Toxicology hydrocarbon years Practically non-toxic, super Poisoning Potential toxic Critical Factors in Substance Concentration Labeling requirements Exposure, duration and frequency Others (flammable, oxidizer etc.) Concentration levels of a substance within biological fluids or at specific target sites B. CHARACTERISTICS OF EXPOSURE Interplay essential for comprehending how substances ROUTE AND SITE OF EXPOSURE accumulate in biological fluids or specific target locations [Batch 2028] Major Routes Ingestion through the gastrointestinal tract Challenges in Human Exposure Assessment Inhalation into the lungs Frequency and duration of exposures often lack the Topical, cutaneous, or dermal contact with skin precision seen in controlled animal studies. Parenteral administration (e.g. intravenous, intramuscular, ○ Due to the inherent variability in the frequency and etc.) duration of exposures Toxic agents generally produce the greatest effects and the ○ Less clearly defined, necessitating careful consideration most rapid response when given directly into the of similar terminologies for describing the overall bloodstream via the intravenous route exposure context ⭐️ Descending Order of Toxicity Effectiveness Similar terminology is employed to describe the general exposure scenario [Batch 2028] 1. Parenteral (most potent) 2. Inhalation Dosage 3. Intraperitoneal Dose-Response Relationship ⭐️ 4. Subcutaneous ○ : The intricate connection between exposure 5. Intramuscular characteristics and the spectrum of events gives rise to a 6. Intradermal crucial correlation known as the dose-response 7. Oral relationship. 8. Dermal (least potent) ○ This relationship represents the consistent link between the degree of response and the quantity of administered Impact of Vehicle and Formulation toxin in a biological system, standing as a fundamental The vehicle or the material in which the chemical is and pervasive concept in toxicology. dissolved along with other formulation factors, can Dosage is the most critical factor in determining whether markedly alter absorption. the intrinsic potential of a substance will be expressed Unit of chemical/unit of biological system (mg/unit body Route’s Influence on Toxicity weight; mg/body surface area; mL/unit body weight, etc.) The route of administration can influence the toxicity of agents. VIII. COMMON ENVIRONMENTAL TOXICANTS ○ For example, an agent that acts on the central nervous A. PESTICIDES system but is detoxified in the liver, is expected to be Any substance or mixture of substances intended for less toxic when administered orally than when inhaled. preventing, destroying, repelling, or mitigating any pests ○ The oral route allows the substance to pass through the Proper and safe use of pesticides can benefit the liver before entering systemic circulation and the central environment, but they pose a major potential for nervous system. environmental pollution Chemicals are increasingly used by 3rd world countries DURATION AND FREQUENCY OF EXPOSURE ⭐️ Table 10. Exposure Types Relative to the Duration and Frequency Most commonly used and manufactured in the Philippines: organophosphates & organochlorines EXPOSURE DURATION DESCRIPTION Most exposed population groups: formulators & farmers TYPE 6 major areas in the environment that require protection Single dose or repeated from mishandling and misuse of pesticide: exposure for slightly toxic or 1. Soil non-toxic chemicals. 2. Water Typically resulting from a 3. Air Less than Acute Exposure single incident or episode. 4. Beneficial Insects 24 hours For inhalation route, 5. Plants continuous exposure for 6. Wildlife less than 24 hours (commonly 4 hours) Repeated exposure to a Sub-Acute Up to 1 chemical for a duration of one Exposure month month or less Several Repeated exposure extending Sub-Chronic weeks to to several weeks or 1 to 3 Exposure 1-3 months months More than 3 Prolonged exposure to the Chronic months or chemical, lasting for more than Exposure years 3 months or extending into Page 4 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO  PCM 2.07 Environmental Toxicology lead-glazed ceramics MERCURY (Hg) It is also known as quicksilver or metallic mercury Liquid state at room temperature - vapor is much more hazardous in liquid form Nonflammable Produces poisonous gas in fire Evaporation of metallic mercury occurs to some extent at room temperature Table 12. Sources of mercury and their categories CATEGORY SOURCES OF MERCURY Antiseptics Calomel teething powders Dental amalgam Figure 3. The pesticide cycle. Medicinal Laxatives Sphygmomanometers B. METALS Thermometers Heavy metals are ubiquitous, they are neither created nor Fish destroyed in the environment. Food Grains and seed, treated Unlike plants, animals, and other organisms, metals cannot Livestock, fed treated grain be degraded beyond their elemental states. Concentration of heavy metals in the environment are Button batteries dependent on natural and anthropogenic cycles, activities, Chemistry sets removal of metals from natural source, alteration, and Lightbulbs Other speciation that can increase its distribution. Self-Injection Examples: aluminum, arsenic, lead, cadmium, mercury Preservatives “Magico-religious” use LEAD (Pb) First heavy metal classified as toxic with reports dating back MERCURY IN GOLD MINING to 300 BC Because gold is heavy, miners use mercury to amalgamate it Characteristics: bluish white, soft metal, gray, strong with the gold, making it easier to capture reducing agent Enters the environment through mercury-coated sieves Since 1980s, Pb use in gasoline, paint, and solder have which is used to strain golds from sediments taken from decreased but not in other parts of the world river bottom and land mining sites Clinically manifests as seizures or convulsions MINAMATA DISEASE Table 11. Sources of Lead In 1908, the Chisso Corporation established a factory in SOURCE DETAILS Minamata, Japan. Leaded paint Especially pre-1978 homes ○ The factory produced nitrogenous fertilizers and quickly ⭐ House dust from grew to become the area's main industry. ○ By the mid-1950s, the Chisso Corporation had become deteriorated lead paint Dust a leader in its industry. ⭐ Dust from clothes/uniform In 1954, reports began to surface of an unknown "epilepsy-like affliction" that would later become known as of workers Minamata disease. From yards contaminated by ○ The cause was unknown, so patients were isolated in an deteriorated lead paint, lead attempt to stop the spread. Soil industry emissions, roadways Minamata disease is a neurological condition caused by with high leaded gasoline mercury poisoning. usage ⭐ Leached from leaded Mercury poisons the central nervous system, impairing balance and motor skills. Water plumbing, cooking utensils, ○ This leads to increasingly intense body convulsions and, water coolers eventually, death. Leaded gasoline, industrial Air In 1957, the Minamata disease research group at Kumamoto emissions University announced that Minamata disease is a toxic Lead solder in cans, “natural” disorder of the central nervous system caused by organic calcium supplements, mercury compounds. They concluded that the compounds Food “moonshine” whisky, lead-foil were transmitted through seafood consumption. covered wines, contaminated The research group isolated organic mercury as the sole flour, paprika cause of the disease through a series of experiments on Folk remedies, cosmetics, cats. ingested foreign bodies, Also in 1957, extremely toxic levels of organic mercury Exotic retained lead bullets, were detected in human patients. substance abuse, leaded ink, ○ A report submitted to the Ministry of Health and Page 5 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO  PCM 2.07 Environmental Toxicology Welfare stated that the underlying cause was organic chemicals mercury in seafood, and the wastewater discharge Setting exposure standards for workplace chemicals from the Chisso factory was suspected as the source. ○ Decision as to what level of human exposure is New patients continued to be discovered until 1960, acceptable for a chemical used in the workplace including babies who were born with brain damage and Biological monitoring for workplace exposure extreme physical disabilities. ○ Decision as to what biological fluids and biologic effects The governor of Kumamoto requested a voluntary ban on should be monitored catches of seafood from Minamata Bay. Understanding and writing material safety data sheets (MSDS) C. SOLVENTS AND VAPORS ○ Recognizing salient information in the MSDS and Class of organic liquid chemicals relating it to worker conditions and potential risk to Classified based on variable lipophilicity, volatility poisoning, such as physicochemical properties, and Examples: methylene chloride, nPB (N-propyl bromide), TCE toxicity data first aid measures (trichloroethylene), toluene, hexane, xylene Identifying job assignments for workers Some solvents are halogenated (i.e. TCE, nPB), others are ○ Potential hazards and workers’ existing health highly addictive conditions should be taken into consideration Sources of exposure: ○ Reproductive hazards should be given emphasis ○ Paints Managing chemical safety in the workplace ○ Varnishes ○ Development of preventive programs in the workplace ○ Adhesives Establishing medical surveillance ○ Pharmaceuticals ○ Perform initial assessment of fitness to work ○ Preservation agents ○ Evaluate effect of work to exposure to harmful ○ Metal cleaning (degreasing) chemicals ○ Household products ○ Appraise whether the worker can continue work in the ○ Industrial and consumer products hazardous area ○ Surface coatings ○ Allow early interventions before adverse effects occur D. TOBACCO SMOKE A. Interventions and Safeguards to Promote Healthy Most preventable cause of death in the world today Environment ○ Kills more than 8M people a year Engineering 1.2M are non smokers exposed to secondhand ○ Actions directed at managing risk-related variables to smoke interpose in technologies for the at-risk population Contains nicotine - highly addictive, psychoactive agent Education ○ Action directed towards voluntary change in the IX. INDIVIDUAL PRACTICES attitudes and behavior of the subject generally by The following are individual practices that may increase our providing information that will lead to favorable change contact with chemicals: Enforcement ○ Improper use of drugs and chemicals ○ Actions directed at mandatory regulation to achieve ○ Mispackaged drugs and chemicals favorable outcomes, which can include, review, and ○ Availability of drugs/chemicals advocate the implementation of regulatory policies, ○ Improper storage of drugs/chemicals laws and conventions for chemicals (i.e. Clean Air Act & ○ Recycling of containers used for drugs/chemicals Stockholm Convention) X. HIERARCHICAL CONTROL OF CHEMICALS REFERENCES Elimination: simplest way to deal with hazard; to get rid of Edmyr M. Macabulos MD, MPH. Notes from Environmental it Toxicology. Substitution: replace a more hazardous chemical/process with a less hazardous chemical/process (e.g. digital LIST OF EQUATIONS thermometer instead of using mercury thermometer) Risk = (Toxicity) x (Exposure) Minimization of inventories: reduce the volume of chemicals being stored SUMMARY Engineering Controls: implemented measures such as Define toxicology and commonly associated terms. segregation of hazardous equipment, alternation, process TERM DEFINITION enclosure/confining work operations Study of adverse effects of toxic chemical, Administrative Controls: job rotations, multiskilling codes Toxicology physical, and biological agents on living of practice organisms Use of Personal Protective Equipment: select a proper PPE for a given chemical; preference for PPE should be indicated in Safe Workplace Policy rather than in Safe Person trained to examine the effects of toxic Worker Policy Toxicologist substances—the cellular, biochemical, and molecular mechanisms XI. IMPORTANT THINGS TO REMEMBER IN THE WORKPLACE Ability of a substance to cause injury to a Toxicity Decision-making within hierarchical control biologic material ○ For control of exposure to toxic substances in the workplace, based on the hierarchical control of Page 6 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO  PCM 2.07 Environmental Toxicology water coolers Toxic substances produced by biologic systems: Leaded gasoline, industrial Toxin phytotoxin (plant), zootoxin (animal), and Air emissions bacteriotoxin (bacteria) Lead solder in cans, “natural” calcium supplements, Any agent capable of causing serious injury to a Food “moonshine” whisky, lead-foil Poison biological system, resulting in loss of function covered wines, contaminated or death flour, paprika Toxic substances produced by or a byproduct of Folk remedies, cosmetics, Toxicant ingested foreign bodies, human activities Exotic retained lead bullets, substance abuse, leaded ink, Overdose of drugs, medicine, chemicals, or Poisoning lead-glazed ceramics biologic substances CATEGORY SOURCES OF MERCURY Probability that a person will be harmed or experience an adverse effect upon exposure to Antiseptics Risk Calomel teething powders a hazard—potential or likelihood that injury will occur Dental amalgam Medicinal Laxatives Amount of chemical that is available for Sphygmomanometers Exposure Thermometers absorption Fish Probability that harm will not occur under Food Grains and seed, treated Safety Livestock, fed treated grain specified conditions— inverse of risk Button batteries Chemistry sets Understand the basic concepts of toxicology and its Lightbulbs sub-discipline of environmental and occupational toxicology. Other Self-Injection Environmental Toxicology Occupational Toxicology Preservatives Study of the impacts of Study of the adverse effects of “Magico-religious” use chemical pollutants in the agents encountered by environment on non-human workers during the course of Sources of exposure to solvents and vapors: biological organisms their employment ○ Paints ○ Varnishes ○ Adhesives Discuss the factors affecting responses to toxic agents. ○ Pharmaceuticals FACTORS EXAMPLES ○ Preservation agents Physical state, solubility, ○ Metal cleaning (degreasing) Chemical & Physical Properties reactivity, vapor pressure ○ Household products Age, sex, nutritional status, ○ Industrial and consumer products Individual Factors genetic background, general ○ Surface coatings health status of the individual Duration, frequency, route, Identify the common types of chemicals and their toxic effects. Exposure Situation dosage TYPE TOXIC EFFECT Accumulate in fat, causing The toxic response depends on the properties of the agent, Pesticides long-term health issues + the exposure conditions, how the body metabolizes it, and environmental pollution the susceptibility of the organism. Cause CNS disorders that manifests as seizures/ Discuss exposure situation to toxic agents. Metals convulsions, impairing balance LEAD and motor skills and eventually SOURCE DETAILS causing death Leaded paint Especially pre-1978 homes ⭐ Respiratory irritation, central House dust from Solvents & Vapors nervous system depression, deteriorated lead paint skin irritation. Dust ⭐ Dust from clothes/uniform Tobacco Smoke Lung cancer, addiction of workers Discuss the preventive measures in environmental and From yards contaminated by occupational toxicology. deteriorated lead paint, lead Elimination: simplest way to deal with hazard; to get rid of Soil industry emissions, roadways it with high leaded gasoline Substitution: replace a more hazardous chemical/process usage ⭐ with a less hazardous chemical/process (e.g. digital Leached from leaded thermometer instead of using mercury thermometer) Water plumbing, cooking utensils, Minimization of inventories: reduce the volume of Page 7 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO  PCM 2.07 Environmental Toxicology chemicals being stored Engineering Controls: implemented measures such as segregation of hazardous equipment, alternation, process enclosure/confining work operations Administrative Controls: job rotations, multiskilling codes of practice Use of Personal Protective Equipment: select a proper PPE for a given chemical; preference for PPE should be indicated in Safe Workplace Policy rather than in Safe Worker Policy FREEDOM WALL CORRECTIONS For suggestions, concerns, or corrections about the contents of this document, please let us know through this Google Form: PrevMed Trans Correction Form Alternatively, you can scan the QR code below to access the form CORRECTIONS HISTORY Nov 2 p3 VII Exposure Concepts (4th bullet, 1st sub-bullet) ○ Deleted “such as.” Note that no information is missing. Version 2 [Nov 3] Table 8 Response-affecting factors and their examples ○ “Individual factors” and “Exposure situation” were switched Page 8 of 8 | TH: VILLAZOR, G. | PCM TG 4 | MANGROBANG, SECONDES, SUNDIAM, TILAO, TURANO