Toxicology for Industrial Hygienists & Safety Professionals

Identify the major routes of exposure— inhalation, skin absorption, ingestion, and subcutaneous entry via puncture—emphasizing inhalation as the most common route and lipophilic chemicals' skin uptake.

Distinguish acute versus chronic chemical effects by latency, local versus systemic outcomes, and additive, synergistic, potentiation, and antagonistic interactions with examples like hydrogen sulfide, asbestos, alcohol, cannabis, atropine.

Explore the dose response curve, including absorbed dose and the exposure-response relationship, showing how exposure levels yield positive or adverse reactions.

Describe the dose-response curve and define the lowest observed effect level (loel) and no observed adverse effect level (noael), comparing outcomes to controls.

Learn that occupational exposure limits are guidelines, not safety thresholds. See how OSHA's permissible exposure limits, NIOSH's recommended exposure limits, and ACGIH's limit values guide worker protection.

Describe the permissible exposure limit (PEL) as a legally enforceable US time-weighted average, and contrast it with the ceiling, short-term exposure limit (SDL), and exclusion limit.

Describe biological exposure indices and biological monitoring to assess chemical exposure, and identify carcinogen classifications such as confirmed human carcinogen, a2 suspected, and e3 animal carcinogen per ecj.

Explore pharmacodynamics and pharmacokinetics, examining how toxicants move through the body by absorption, distribution, and elimination, and how cadmium and organophosphate exposure affect kidneys and neurotoxicity via acetylcholinesterase inhibition.

Identify target organ toxicity and explain why toxicants affect specific organs. The liver's detoxifying role and chemical structure drive organ targeting, such as lead accumulating in bone causing anemia.

Examine hepatic toxicology by detailing liver structure and function, hepatocytes, and phase one and phase two metabolism, and illustrate hypnotoad toxicants with carbon tetrachloride, PVC solvents, and cirrhosis or fibrosis.

Explore how neurotoxicity alters the nervous system, describing central and peripheral divisions, somatic and autonomic controls, symptoms including peripheral neuropathy, and industry exposures.

Explore neurotoxicity by examining how neurotransmitters like acetylcholine transmit signals across the synaptic cleft, and how organophosphate pesticides inhibit acetylcholinesterase, trapping neurotransmitters and halting new impulses.

Conclude neurotoxicity topics by detailing peripheral neuropathy signs, autotoxicity, toxic amblyopia, and alopecia, and review workplace chemicals such as carbon disulfide, lead, arsenic, mercury, organophosphates, ethylene oxide, methanol, and styrene.

Describe the immune system’s basic structure and function and discuss immunotoxicants and exposure, with examples like perchlorate, radiation, and benzene in chemical, nuclear, and food industries.

Examine difference between primary and secondary irritants in pulmonary toxicology, showing primary irritants like hydrogen chloride and ammonia cause local inflammation, while secondary irritants like hydrogen sulfide cause systemic effects.

Describe how respiratory sensitizers trigger airway hypersensitivity after prior exposure, with induction and elicitation. Note examples like metals, cutting oils, and machining fluids in metal shops and foundries.

Explore hematotoxicology and the hematopoietic system, showing how toxicants disrupt red and white blood cell production, platelets and clotting, leading to anemia, including arsenic-induced hemolytic anemia.

Explore cardiovascular toxicology by reviewing the heart, blood vessels, and flow through pulmonary and systemic circuits, and examine how toxins like heavy metals and hydrocarbons induce dysrhythmias and cardiac sensitization.

Explore genetic toxicology by describing gene structure and function, defining carcinogens, mutagens, teratogens, and genotype-phenotype concepts, and outlining the Ames test and mutagenesis assays in industrial health.

Explore dermal toxicology by examining the skin as the largest organ, its barrier functions, and exposure to chemicals; compare contact dermatitis with sensitizer dermatitis, urticaria, and photo-sensitization.

Explain what infectious diseases are and identify causes and symptoms of key diseases caused by bacteria, fungi, viruses, parasites, and prions, such as tularemia and histoplasmosis.

Explain what a heavy metal is, identify common heavy metals in work environments, and describe bioaccumulation and health effects such as anemia, nervous system impact, and respiratory irritation.

Classify pesticides by chemical nature into organophosphates and organochlorines, and show how organophosphates inhibit acetylcholinesterase, causing neurotransmitter toxicity and acute symptoms, with organochlorines as persistent organic pollutants.

Explore organic solvent toxicology, identifying common solvents, their health effects, and volatile, lipid-dissolving properties. Learn about additive solvent interactions, CNS narcotic effects, and a TLV-based formula to assess overexposure.

Identify alpha, beta, and gamma radiation and distinguish ionizing from non-ionizing forms. Learn key measurement units (sievert, rem) and how absorbed dose relates to biological damage via quality factors.

Explore how spirometry, a pulmonary function test, measures ventilation capacity and how asthma, silicosis, and asbestosis affect FEV1, FVC, and peak expiratory flow to identify obstructive or restrictive patterns.

Explain the importance and limitations of biological monitoring and how biological exposure indices assess absorbed chemicals, noting rapid metabolism and non-specific metabolites.

Celebrate completing this toxicology course and encourage those pursuing the C.H. or the CSP to prepare for their exam.

Explore how chemicals move through ecosystems, defining eco toxicology, bioaccumulation, bio concentration, and bio magnification, and examine the entry, distribution, fate, and effects on organisms, populations, and ecosystems.