Day 2 Occupational Health Hazards.ppt

OCCUPATIONAL HEALTH HAZARDS

Occupational Health Hazard  conditions that cause legally compensable

illnesses  any conditions in the workplace that impairs the health of employees enough to make them loss time from work or to work at less than full efficiency

OCCUPATIONAL HEALTH  Occupational Health is the division of

Occupational Safety and Health that deals with the control of health hazards in the workplace.  Two very important terminologies in Health Occupational: – Industrial Hygiene – Occupational Medicine.

Industrial Hygiene  Science and art devoted to the

anticipation, recognition, evaluation and control of environmental factors or stresses arising in or from the workplace which may cause sickness, impaired health and well being or significant discomfort among workers or among citizens of the community.

Role of the Industrial Hygienist to the Industrial Hygiene Program  To protect the health of the employees  To maintain an objective toward the

recognition, evaluation and control of health hazards regardless of external influences, realizing that the health and welfare of workers and others may depend upon the industrial hygienist professional judgment.

Role of the Industrial Hygienist to the Industrial Hygiene Program  To counsel employees regarding the health

hazards and the necessary precautions to avoid adverse health effects  To respect confidences, advise honestly and report findings and recommendations accurately  To act responsibly in the application of the industrial hygiene principles toward the attainment of healthful working environment

Role of the Industrial Hygienist to the Industrial Hygiene Program  To hold responsibilities to the employer or

client subordinate to the ultimate responsibility to protect the health of the employees.

Hazard  This is the probability that this

concentration in the body will occur

Environmental Stresses or Hazards Chemical Hazards

Physical Hazards Biological Hazards

Ergonomic Hazards

Chemical Hazards  Arise from excessive airborne concentration

of mists, vapors, gases or solids that are in the form of dusts or fumes.  The hazard of inhalation,  Skin irritants  Toxic by absorption through the skin

“Industrial Toxicity” is the key to understanding the effects of chemicals

Toxicology  Science that deals with the poisonous or

toxic properties of substances.  Everyone is exposed on and off the job to a variety of chemical substances;

Toxic Effect  Any noxious effect on the body – reversible or

irreversible,  Any chemical included tumor, benign or malignant,  Any mutagenic or teratogenic effect or death – as a result of contact with a substance via the respiratory tract, skin, eye, mouth or any other route.

Toxicity  The ability of a substance to produce an unwanted effect when the chemical reached a sufficient concentration at a certain site in the body.

Contributing Factor to Determine the Degree of Hazard of a Chemical  Routes of entry

 Toxicity

 Dosage

 Chemical

 Physiological state

properties  Physical properties  Warning properties

 Environmental

variables

Routes of Entry into the Body  Ingestion  Injection  Skin absorption  Inhalation

Action of toxic substance  Acute toxicity – Short-term exposure to a high concentration with an immediate effect  Chronic toxicity – Effects manifests over a period of time

Exposure  The contact between a person/test animal

and a substance such as gases, vapors, dust, etc.

Factors Affecting Exposure • Concentration • Duration of Exposure • Route of Entry • Individual Susceptibility

Factors Affecting Human Susceptibility  Age  Sex  General health  Genetic variability  Anatomic variability

 Nutrition  Previous exposure

Classification of Toxic Effects Local – When a certain chemical harms only the part of the body it comes in contact with. (Ex: acid burns on skin) Systemic – When a certain chemical harms other related organs operating as a system. (Ex: Carbon Monoxide – affects the blood and the CNS.)

Specific Organ Toxicity  Skin  Liver  Respiratory tract  Nervous system  Kidneys

 Blood

Threshold level  The level where the first effect or response

to a toxic substance is observed or detected

Threshold Limit Values (TLVs) Refer to airborne concentration of

substances and represent conditions under which it is believed that nearly all workers maybe repeatedly exposed day after day without adverse effect

Threshold Limit Values (TLVs) The basis on which the values are

established may differ from substance to substance; Basis may be : – protection against impairment of health – reasonable freedom from irritation, narcosis, nuisance or other forms of stress

Threshold Limit Value - Time Weighted Average (TLV-TWA)  The time weighted average concentration

for a normal 8-hour workday and a 40-hour workweek, to which nearly all workers maybe repeatedly exposed, day-by-day, without adverse effects.

Threshold Limit Value – Short Term Exposure Limit (TLV-STEL)  The concentration to which workers can be

exposed continuously for a short period of time without suffering from irritation, chronic or irreversibly tissue damage, and narcosis of sufficient degree to increase the likelihood of accidental injury, impairs selfrescue or materially reduce work efficiency, and provided that the daily TLV-TWA is not exceeded

 Note: STELs are recommended only where

toxic effects have been reported from high short-term exposures in either humans or animals – 15 minutes and should not be repeated more than 4 times a day

Threshold Limit Value – Ceiling (TLV-C)  The concentration that must never be

exceeded during any part of the working exposure  “Skin” Notation – Refers to the potential contribution to the overall exposure by the cutaneous route including mucous membranes and eye, either by airborne, or more particularly, by direct contact with the substance.`

Simplified diagram of metabolic pathways in the body INHALATION

WOUNDS & SKIN ABSORPTION

INGESTION

Upper Respiratory Tract

Lung (Storage)

Body Fluids

GI

Organs (Other than lung), bone tissues (Storage)

Exhalation

Urine

Feces

Principal Pathways Supplementary pathways depending on chemical & physical composition

Dose – Response Relationship The dose response relationship can be

expressed as the product of a concentration (C) multiplied by the duration of exposure (T). The dose involves two variables – - concentration and duration of exposure.

PHYSICAL HAZARDS  Noise  Extremes of Temperature

 Vibration  Radiation

Sound vs. Noise  Sound is any pressure variation (in air,

water or some other medium) that the human ear can detect. It is a stimulus that produces a sensory response in the brain.  Noise is an unwanted sound because it is unpleasant. It interferes with the perception of wanted sound, and is likely to be physiologically harmful.

Effects of Noise on Man The

masking of wanted sounds, particular speech Auditory fatigue & damage to hearing Excessive loudness Annoyance

Facts on Sounds  Decibels (db) – used to express the sound

level associated with noise measurements.  Normal hearing 20 hz – 20,000 hz.

 Loudness depends primarily on sound

pressure and frequency (pitch).

Measuring Noise Levels  A - Weighting

It has become a popular measure for assessing the overall noise hazard since this provides a rating of industrial broadband noises in a manner reasonably similar to its injurious effects on the human ear.

Noise Standards Philippine OSHA

90 dB(A) US OSHA

Most US companies use 85 dB(A)

Critical Factors in the Analysis of Noise Exposures  A – weighted sound level

 Frequency composition or spectrum of the

noise  Duration and distribution of noise exposure during a typical workday.

General Classification of Noise Exposure  Continuous Noise  Intermittent Noise  Impact – type Noise – a sharp bust of sound

The Hearing Conservation Program  Walk through survey Noise Measurements  Identification of Personnel for Audiometric

Monitoring  Posting of Noise Hazardous Areas and Labeling of Noisy Equipment  Use of Personal Protective Equipment, such as plugs and muffs

EXTREMES OF TEMPERATURE Coldness A condition suffered by workers exposed to extremely cold temperatures.

Heat Stress It is a combination of physiological environmental forces or loads, which exert a strain upon the human body as our systems try to compensate.

Thermal Comfort  A comfortable environment resulting from

the simultaneous control of temperature, humidity, and air distribution within the workers vicinity.  This set of factors includes main radiant temperature as well as the air temperature

Variables Affecting Thermal Comfort Season of the year

Dry & wet bulb temperatures Cultural practices and habits

The Physiology of Heat Stress  Prevention of the body’s heat – regulating

mechanisms from working efficiently.  Excessive heat gains within the body.

Mechanisms Involved in Heat Transfer  Conduction - The transfer of heat from one point to

another within a body or from one body to another when both bodies are in physical contact.  Convection - This involves the transfer of heat from one place to another by moving gases or liquid.  Radiation - The process by which energy electromagnetic (visible and infra red) is transmitted through a space without the presence or movement of matter in or through this space.

Two Sources of Heat  Metabolic Heat - is a by–product of the

chemical processes that occur within cells, tissues and organs.  Environmental Heat - influences the rate at which body heat can be exchanged with the environment and consequently, the ease with which the body can regulate and maintain a normal temperature

Manifestation of Cold Stress • Constriction of the blood vessels. • Shivering • Slowed nerve impulses • Sluggish reaction • Fumbling hands • Clumsiness

Cold & Heat Stress Prevention  Acclimatization  Increase fluid intake

 Salt intake  Eating a well balanced diet  Engineering & administrative Measures

Measurements of Temperature  A temperature reading called the WET

BULB GLOBE TEMPERATURE (WBGT) INDEX should be obtained.  The WBGT index is used as a parameter to adjust work practices according to the prevailing environmental conditions

RADIATION  Ionizing Radiation (Particle radiation and

wavelike radiation)  Non - Ionizing Radiation

Ionizing Radiation  Particle Radiation – Fast electrons – Beta particles – Alpha particles  Wavelike Radiation – X-rays – Gamma rays

Non - Ionizing Radiation Radio wave Microwave

Infrared waves Visible light

Ultraviolet light

Biological Hazards These include insects,

molds, fungi, virus, and bacterial contamination.

Ergonomic Hazards  These include improperly designed tools or

work areas.  Improper lifting or reaching, poor visual conditions or repeated motions in an awkward position .

Ergonomic Related Disorders –Carpal Tunnel Syndrome –Tendonitis –Lower back problems

INDUSTRIAL HYGIENE CONTROL METHODS  Engineering Controls

 Administrative Controls  Personal Protective Equipment

Engineering Controls  Substitution - involves the substitution of

hazardous materials with one that is less hazardous.  Isolation - involves the physical isolation of the process or the worker using enclosures

Engineering Controls  Ventilation - involves the introduction of

fresh air to dilute, exhaust or remove the contaminated air. – General Ventilation – Local Exhaust  Change the Process - involves the switching of an operation to a less hazardous operation.

Administrative Controls  Rotation of Personnel  Limiting the time spent (of personnel) in

the hazard areas  Good housekeeping and maintenance including cleanliness in the workplace, proper waste disposal and adequate washing, toilet and eating facilities.

Administrative Controls  Special control methods for specific

hazards, such as shielding, monitoring devices and continuous sampling with preset alarms.  Medical controls to detect evidence of absorption of toxic materials.  Training and education to supplement engineering controls.  Emergency response training and education.

Personal Protective Equipment  Eye and face protection  Protective clothing/gloves

 Hearing protective devices  Protective creams and lotions  Respiratory protective devices