Understanding Ergonomics and Industrial Diseases

UNDERSTANDING ERGONOMICS AND INDUSTRIAL DISEASES

1. INYANG A. UKOT, M.B.; B.S., FMCGP, FWACP(GMP), DOccMed.(Lond.)

CHIEF CONSULTANT, FAMILY MEDICINE

• Ergonomics is the science of work.
• Industrial diseases are diseases that are attributable to work.

INTRODUCTION

• Ergonomics is the science concerned with the “fit” between people and their work. It gives priority to people and takes their capabilities and limitations into consideration.
• The aim of Ergonomics is to ensure that:
  • tasks,
  • equipment,
  • Information, and
  • the environment suits every worker.
• When there is no fit or there is a misfit between the work and the worker there is the tendency for industrial diseases and/or accidents to occur.
• Industrial diseases may be acute but, frequently, they are chronic or long-standing in course while accidents occur suddenly but may have long-term negative effects on the work and the worker.
• An understanding of ergonomics in the workplace can improve daily work routine.
• It is possible to eliminate aches, pains, and stresses at work and improve efficiency, productivity, and job satisfaction.

ERGONOMICS AND DESIGN

• Human Factors/Ergonomics should be applied right at the design of tasks, equipment, etc.
• Designing tasks, equipment, and workstations to suit the user can reduce human error, accidents, and ill-health.
• Poor design contributes to work-related ill-health and has been found to be a root cause of accidents, including major accidents.
• Users should be involved in the design process. This should include different types of users including operatives, maintenance, and systems support personnel.
• Consideration should be given to all foreseeable operating conditions including upsets and emergencies.
• During design, consideration should also be given to the interface between the end user and the system.
• Ideally the end-user/operator of a machine or some other industrial equipment should be involved in the design of the equipment.
• When the above is not possible they should be involved in the re-design of machines and other equipment by giving input into problems encountered during the actual operation of various equipment.
• When employees or staff at any level in an organization know that useful input provided by them is taken seriously and used for improvement of equipment, they see themselves as useful members of the establishment and enjoy their jobs better.
• The employer and employees who work towards continuous improvement in tools and machines (no matter how basic), working conditions, etc. are actually aiming at increased productivity.

ERGONOMICS AND FATIGUE

• Fatigue refers to the issues that arise from excessive working time or poorly designed shift patterns.
• It is generally considered to be a decline in mental and/or physical performance that results from prolonged exertion, sleep loss and/or disruption of the internal “clock.”
• Fatigue is also related to workload, as workers are more easily fatigued if their work is machine-paced, complex or monotonous.
• Fatigue results in:
  • slower reactions,
  • reduced ability to process information,
  • memory lapses,
  • absent-mindedness,
  • decreased awareness,
  • lack of attention,
  • underestimation of risk,
  • reduced coordination, etc.

WORK SCHEDULES

• Poorly designed shift-working arrangements and long working hours that do not balance the demands of work with time for rest and recovery can result in the following:
  • fatigue,
  • accidents,
  • Injuries, and
  • ill health.
• Problems with overtime and shift-swapping may indicate inadequate resource allocation and staffing levels.
• The term “staffing levels” refers to having:
  • the right people
  • in the right place
  • at the right time.
• Key risk factors in shift schedule design, which must be considered when assessing and managing the risks of shift work include:
  • workload
  • work activity
  • shift timing and duration
  • direction of rotation
  • number and length of breaks during and between shifts
  • physical environment
  • management issues, and
  • employee welfare

WORK-WORKER FIT

• To have a good fit the following are important:
  • the job being done and the demands on the worker;
  • the equipment used (its size, shape, and how appropriate it is for the task);
  • the information used (how it is presented, accessed, and changed);
  • the physical environment (temperature, humidity, lighting, noise, vibration); and
  • the social environment (such as teamwork and supportive management).

WORKERS’ PHYSICAL FEATURES

• The physical attributes of the worker are important:
  • body size and shape;
  • fitness and strength;
  • posture;
  • the senses, especially
    • vision,
    • hearing, and
    •  
  • the stresses and strains on
    • muscles,
    • joints, and
    •  

EMPLOYEE VULNERABILITY

• Employees tend to “naturally” protect themselves to a reasonable extent when they see, hear, smell, or feel a hazardous agent.
• The earlier part of this presentation is easier for most employers and employees to appreciate.
• The next part of the presentation is more technical and could be more subtle; that is why a trained occupational physician is an asset to organizations and workers that deal with metals, chemicals, etc.
• Employee vulnerability is reduced or removed when the following happen:
  • The employer puts in place mitigating factors against exposure of the employer, employees, and third parties to hazards;
  • The employer and employees know established exposure limits are abide by them;
  • The employees in particular know the risks that exposure to chemical, metal, and other hazardous materials subjects them to in the short-term, medium-term, and long-term.

WHO IS MOST LIKELY EXPOSED?

• At the level of obtaining metals in the raw form the most likely persons to be exposed are “miners.”
• The above sentence holds true in certain parts of the developing world where there is gross exploitation of poor people who accept any kind of work just to eke out a living.
• It is only in such situations that exposure could be abnormally high, and the workers are oblivious of the risks the “employment” subjects them to.
• As you follow the next stage of this presentation the products that contain the metals and chemicals discussed should make you figure out who else can be exposed to them.
• It is important to note that these agents are constituents of products that are widely used.
• Those who are exposed are therefore not only employees who produce, store, or warehouse these chemicals and metals for various manufacturing processes/plants.

MODE OF EXPOSURE

• Exposure of the body to metals and chemicals is by one or more of the following:
  • Inspiration (Breathing)
  • Skin or mucous membrane exposure
  • Ingestion (By mouth or eating)
• In a standard administrative office, employees are relatively free from metals and chemicals; in factories, warehouses, chemical plants, etc. robust protection mechanisms should be put in place.

LEAD

• Reticuloendothelial system effects
  • Anemia from inhibition of delta-amino-laevulinic acid hydratase.
  • Neurotoxicity – This leads to a primarily motor neuropathy
  • GI effects – Constipation, Abdominal colic
• Reproductive effects
  • Male: Reduced sperm count; reduced sperm motility; increased abnormal forms
  • Female: Reduced fertility; early fetal loss; fetal developmental abnormalities

IRON

• Iron is corrosive to the GIT
• It is rapidly absorbed in the GIT
• Toxicity from Ingestion or Environmental exposure
• Most overdoses ß children mistaking tablets for candy/ “sweets”
• Other sources:
  • Drinking water
  • Iron pipes
  • Cookware
  • Target organs for toxicity:
  • The CVS
  • Liver
  • Kidneys

COPPER

• Sources of exposure to copper:
  • Copper wire
  • Insecticides
  • Fungicides
• Symptoms of copper toxicity
  • Skin: Greenish discoloration of hair.
  • Ingestion: Abdominal pain, Nausea, Diarrhea, Vomiting.
  • Other symptoms: Convulsions, Fever, Weakness, Metallic taste, Renal failure, Shock.
• Treatment principles:
  • Activated charcoal
  • Antidote
  • Gastric lavage
  • Symptomatic treatment
  • Dialysis

Most of the above principles are useful in acute exposure

during accidents but chronic exposure is the situation in

the workplace/occupational setting.

HALOGENATED AROMATIC HYDROCARBONS (HAHs)

• HAHs are chemicals that contain one or more atoms of a halogen and a benzene ring.
• Halogens: Chloride, Fluoride, Bromide, and Iodide.
• Examples of HAHs:
  • Chlorobenzene,
  • Hexachlorobenzene,
  • Dichlorodiphenyltrichloroethane (DDT),
  • Hexachlorophene,
  • Polychlorinated biphenyls (PCBs), and
  • Polybrominated biphenyls (PBBs)
• Uses:
  • Chlorobenzene: Solvents and chemical intermediates
  • Dichlorobenzene: Solvents and chemical intermediates, Fumigants, Disinfectants, Insecticides
  • Hexachlorobenzene: Fungicide, Intermediate for dyes, Raw material for synthetic rubber, Plasticizer for PVC.
  • Dichlorodiphenyltrichloroethane (DDT): Insecticides, Drugs against lice.
  • Hexachlorophene:

            *Topical anti-infective agent

            *Detergent

            *Antibacterial agent for soaps, surgical scrubs, hospital equipment, cosmetics

• Polychlorinated biphenyls (PCBs):

            *Electrical transformers

*Capacitors

*Fluorescent light ballasts

*Hydraulic fluids

*Lubricating oils

*Cutting oils

*Microscope immersion oil

*Fire retardants

*Printing inks

*Carbonless copy paper

*Paints

*Coating of wood, metal, and concrete.

They are bacteriostatics, fungistatics, and pesticide synergists.

• Toxic effects of HAHs:
• As a group the following are toxic effects of halogenated aromatic hydrocarbons in humans:
• Acute irritation of eyes, mucous membranes, and lungs.
• GI symptoms e.g., nausea.
• Neurological symptoms e.g., headache and CNS depression.
• Acne (chloracne).
• Liver dysfunction – Jaundice, hepatitis.
• Reproductive disorders – Abortions, stillbirths, low birth weight (LBW).

PETROL (GASOLINE)

• Petrol is a product of crude oil refining
• Cars – Significantly used in internal combustion engines
• Some people choose to sniff petrol, etc.
• Long term effects of sniffing petrol:
  • Neuronic damage
  • Seizures
  • Tremors and poor co-ordination
  • Amnesia
  • Apathy, mood swings, and aggression

PREVENTION OF ILLNESS FROM METALS AND CHEMICALS

At The Workplace:

• No smoking, eating, or drinking at work
• Correct use of PPE
• Availability of showering facilities
• Separation of work clothes and street clothes storage areas
• Prompt reporting of exposure
• Early treatment by physicians well versed in issues of occupational medicine

At Home:

• Use the least harmful product possible
• Purchase required quantity only
• Read labels and know the hazards
• Store in original container only
• Use established disposal facilities only
• Know symptoms of toxicity
• Know first aid measures

CONCLUSION

Good ergonomics sense makes good economic and health sense

RESOURCES/REFERENCES

• Understanding ergonomics at work HSE
• Managing shift work: Health and Safety Guidance HSG 256
• Improving alertness through effective fatigue management.
• Fundamentals of shift work scheduling.

Dr. Inyang Ukot

September 2022