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for Pedagogues and School Staff for Pedagogues and School Staff for Pedagogues and School Staff for Pedagogues and School Staff Joel Klein Chancellor

Toxicology Toxicology

Definition Definition Toxicology is the study of the harmful effects of Toxicology is the study of the harmful effects of chemicals on biological systems chemicals on biological systems 33 33 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

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How do Chemicals Enter The Body? How do Chemicals Enter The Body? Absorption Inhalation Ingestion Injection Toxic substances can Toxic liquids can cause get into your body if you You can breathe toxic Toxic substances can damage if they come into eat or smoke without dusts, gases, or fumes. get into your body if you contact with your skin or washing contaminated eat or smoke without eyes. hands . These can harm your washing contaminated respiratory system or hands. Some toxic liquids can pass pass from your lungs into through your skin and enter your bloodstream and the bloodstream and cause harm another part of harm to another part of the your body. body. 35 35 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Physical Manifestations of Physical Manifestations of Chemicals Chemicals

Vapors Gases � � The gaseous form of substances that Gases can be inhaled are normally in the solid or liquid state at room temperature. � Some gases are: � easy to detect � The vapor can be changed back to � some are odorless and colorless the solid or liquid state either by � some even deaden your sense of increasing or decreasing the temperature alone. smell � Vapors can be inhaled 37 37 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Solids � A solid is a material which retains its form, such as a stone. � Most solids are generally not hazardous since they are not likely to be absorbed into the body. � Examples of hazardous solids: – Moth balls – inhalation hazard – Rodent bait – ingestion hazard 38 38 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Dusts Fumes � � Fumes are formed when a solid, Dusts are tiny solid particles that can especially metals are heated to very be inhaled. high temperatures and become vaporized. � Larger dust particles are trapped in � Example: welding fumes the mucous and hairs of the nose and windpipe. � Fumes can be inhaled. � Smaller dust particles can be breathed deeply into the lungs . 39 39 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Basic Defense Mechanisms Basic Defense Mechanisms

The Respiratory System The Respiratory System Upper Respiratory System Lower Respiratory System Upper Respiratory System Lower Respiratory System � Cilia � Cilia � Coughing � Coughing � Mucous � Mucous � Sneezing � Sneezing � Muco � Muco- -cilliary cilliary escalator escalator � Nose hairs � Nose hairs Trachea � Mucous � Mucous Bronchi Alveoli Level Alveoli Level � � Immune System Immune System � � macrophages macrophages 41 41 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Skin Skin � � Largest body organ Largest body organ � � Waterproof protective layer against: Waterproof protective layer against: � � Organisms Organisms � � Chemicals Chemicals � � Overexposure to solvents denaturizes Overexposure to solvents denaturizes the skin, leading to: the skin, leading to: � � Cuts Cuts � � Breaks Breaks � � Dry skin Dry skin 42 42 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Dose- -Response Relationship Response Relationship Dose The greater the amount of a substance The greater the amount of a substance that enters the body, that enters the body, the greater is the health effect on the body the greater is the health effect on the body 43 43 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Types of Health Effects Types of Health Effects

Sensitization Synergistic � This is another word for allergy � Two or more agents that act � Some people are allergic to a together to produce a total effect particular substance while others greater than the sum of the are not separate effects. � Allergic responses may not have an � Example: effect after the initial exposure, but later contact with the substance � ethanol + chlorine = chloroform may cause an allergy to develop � ammonia + bleach = chlorine gas 45 45 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Additive Antagonistic � � The effects of multiple chemicals Interaction of two chemicals in at a time or the effects of the which the resultant toxic effect is different hazards may be lower than the chemicals’ additive. individual actions. � Example includes: � Examples: � Methanol and ethanol � 3 + 6 = 9 exposure. � Colorants-inorganic or organic matter to color compounds . 46 46 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Mutagens Teratogens � � These substances cause Mutagens causes a change in the malformations or birth defects genetic make-up of a cell by damaging the developing embryo � In reproductive cells (sperm or eggs), the mutagen can cause � Example: Thalidomyde sterility or birth defects � Example: x-rays 47 47 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Carcinogens Target Organs � � The organ of the body most Cancer causing agents affected by the exposure to a � particular substance. A chemical is considered to be a carcinogen if it has been � Target organs are body organs positively evaluated by: that are affected by exposure to hazardous chemical, physical, � International Agency for or biological agent. Research on Cancer (IARC), � Example: � Annual Report on � Mercury – neurological Carcinogens,by the National � Hepatitis - liver Toxicology Program (NTP) � OSHA Example : Asbestos 48 48 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Types of Target Organ Effects Types of Target Organ Effects HEPATOXINS liver NEPHROTOXINS kidney NEUROTOXINS nervous system damage PULMONARY lung damage HEMATOPOIETIC blood system damage REPRODUCTIVE TOXINS reproductive system CUTANEOUS HAZARDS skin damage OPTICAL HAZARDS eye damage 49 49 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Exposure Assessment Exposure Assessment & Control & Control

Biological Threshold Level Biological Threshold Level Some substances have measurable Some substances have measurable exposure levels below which most people exposure levels below which most people will not likely show any health effects will not likely show any health effects PEL - - Permissible Exposure Levels Permissible Exposure Levels PEL An exposure limit published and enforced by OSHA as a legal standard TLV - - Threshold Limit Value Threshold Limit Value TLV A time-weighted average guideline concentration under which most people can work consistently for 8 hours a day for 40 hours with no harmful effects 51 51 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Determining Exposure Determining Exposure

Practical Clues to Exposure Practical Clues to Exposure Odor Not reliable as a warning clue Settled Dust Immediate symptoms Particles in Nose Taste 53 53 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Environmental Monitoring Environmental Monitoring Air Sampling Performed by an Industrial Hygienist Personal Air Sampling Direct Reading Area Sampling Immediate quantification Worn by workers to Analyzed by a laboratory of air pollutant measure individual’s actual exposure 54 54 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Biological Monitoring Biological Monitoring BLOOD EXHALED AIR URINE SPUTUM Chemical levels and/or its breakdown products are measured Example: blood lead levels 55 55 Office Occupational Safety and Health - - 2008 2008 - - 2009 2009 Office Occupational Safety and Health

Controlling Exposure Controlling Exposure