Environmental Health Overview

Overview of Environmental Health

• "Environment" originates from old French; "En" means "In," and "Viron" means "Circle."
• "Environment" includes circumstances, objects, or conditions surrounding one.
• Factors like climate, soil, and biotic elements acting on an organism or ecological community constitute the "environment."
• "Environment" represents the total natural conditions where animals live, including climatic, geographic, and faunal aspects, and everything external to an individual human host.
• In public health, the "environment" includes all external factors, physical, social, and cultural, which influence health status in populations.
• The World Health Organization (WHO) defines "environmental health" as the aspects of human health, including quality of life, determined by physical, biological, social, and psychosocial factors in the environment.
• Environmental health involves assessing, correcting, controlling, and preventing environmental factors that can adversely affect the health of current and future generations.
• Environmental health is the branch of public health concerned with the impact of both the natural and built environment on human health.
• Essential elements of environmental health science are factors in the environment affecting human health.
• Factors include pollutants or toxicants in air, water, soil, food, plants, or animals,
• These factors are transferred to humans by inhalation, ingestion, or absorption.
• Branches of environmental health include:
  • Environmental epidemiology.
  • Toxicology.
  • Exposure science.
  • Environmental engineering.
  • Environmental law.
• Environmental epidemiology studies the relationship between environmental exposures (chemicals, radiation, microbiological agents, etc.) and human health.
• Toxicology studies how these environmental exposures lead to specific health outcomes, largely in animals, to infer possible health outcomes in humans.
• Exposure science identifies and quantifies human exposure to environmental contaminants.
• Environmental engineering applies scientific and engineering principles to protect human populations from adverse environmental factors, protect environments from deleterious effects, and improve environmental quality.
• Environmental law includes treaties, statutes, regulations, common and customary laws addressing the effects of human activity on the natural environment.
• Contributors to the environment:
  • Physical: air, water, soil, flora, fauna, housing, climate, geography, heat, light, noise, debris, air pollutants, smoke, toxic gases,toxic effluents, pesticides etc.
  • Biological: viruses, bacteria, other microbes, insects, rodents, animals, plants, disease producing agents, reservoir of infection, intermediate host and reservoirs of infection
  • Social/psychosocial/socioeconomic: culture, values, customs, habits, morals, religions, education, lifestyle, community life, health services, social and political organizations.
• Basic requirements of a clean environment are:
  • Clean air.
  • Safe and sufficient water.
  • Safe, nutritious, and accessible food.
  • Safe and strong settlements.
  • Stable global environment.
• The scope of environmental health includes:
  • Water supplies.
  • Waste water treatment.
  • Waste management.
  • Vector control.
  • Prevention and control of land pollution.
  • Food hygiene and safety.
  • Air quality management.
  • Environmental radiation hazards.
  • Environmental noise management.
  • Accommodation establishments.
  • Environmental Impact Assessments.
  • Environmental health aspects of public recreation and tourism.
  • Environmental health measures associated with epidemics, emergencies, disasters and migrations of populations.
  • Establishment of an effective environmental health surveillance and information system.
  • Research on environmental health issues

Overview of Occupational Health

• Ramazzini, in the 18th century, is considered the father of occupational medicine.
  • He published the first systematic account on occupational diseases called De Morbis Artificum/Disease and Occupation.
  • Ramazzini emphasized obtaining occupational histories and introduced the practice of doctors visiting workplaces.
• Hippocrates, from 470 to 410 B.C., was a Greek physician
  • He stated that doctor were to ask patients about their job
  • He is known as the father of medicine.
  • Observed lead poisoning among miners
• Pliny the Elder who lived from 23 to 79 A.D.
  • He stated that miners should use an animal bladder to cover their mouth
  • Dangers related to zinc and sulfur
  • Is a Roman senator, writer and scientist
• Georgius Agricola (1494-1555)
  • Environmental contamination should be looked into
  • Need for ventilation and fresh air in mines
  • Ergonomics, mechanical lift processes should be introduced
  • Wrote De Re Metallica which looked into mining, smelting and refining
• Paracelsus (1493-1591) : All substances are poisons if the right dose is not administered .
  • Established concepts of acute and chronic toxicity
  • Is the father of Toxicology
• Bernardino Ramazzini who lived from 1633-1714 - wrote Diseases of Workers
  • Doctors should "Of what trade are you"
  • Linked occupational diseases to handling of harmful materials
  • Occupational Medicine original father
• Percival Pott (1713-1788) -chimney sweep,
  • He linked Occupation, toxin to (poly-aromatic hydrocarbons) and testicular cancer
• Alice Hamilton championed social responsibility
  • She investigated the cause and effect of worker illness.
  • Named first woman to Harvard Medical School
  • Investigated lead and silica hazards
  • Founder of Industrial Hygiene and wrote "Exploring the Dangerous Trades"
• Since 1950, the International Labour Organization (ILO) and the World Health Organization (WHO) have shared a common definition of occupational health.
• The Joint ILO/WHO Committee on Occupational Health adopted it in 1950 and revised in 1995.
• Occupational health definition:
  • Aim for the promotion and maintenance of the highest degree of physical, mental and social well-being
  • Prevention amongst workers of departures from health caused by their working conditions
  • Adapted to workers employment to health
  • The planning and maintenance of workers in an occupational environment adapted to his physiological equipment
  • Adapting work to man, instead of man to work
• Occupational Health is explained as problems arising from or pertaining to work
  • Health of the gainfully employed
  • Health of people at work
  • Relationship between Occupation (work) & Health
• Gloomy reality of Occupational Health:
  • No man without occupation.
  • No occupation without Hazards.
  • No treatment for occupational disease
• Rosy truth of Occupational Health:
  • Occupational Disease can be prevented
• Occupational health in Nigeria:
  • The first National Industrial Safety Conference was in 1962 -1st International Seminar on Occupational Health in the developing Countries 1968, Lagos
  • Division of Occupational & Environmental Health 1976
  • Institute of OH, Oyo State, 1983
• The most important aims of occupational health are promoting and maintaining the highest degree of physical, mental, and social well-being of workers in all occupations.
• Interaction between work and health:
  • Good physical ability, creativity contribute towards the productivity cycle
  • Relief of boredom, creativity, and personal gain from work.
  • Poor health on work – incapacity, low productivity, worsening of illness, danger to others.
  • Negative effects of work can occur due to many hazards
• Positive effects of good health on work – physical ability, creativity, fueling the productivity cycle
• The principal disciplines in occupational health include:
  • Nurses.
  • Physicians.
  • Hygienists.
  • Engineers/Ergonomists.
  • Psychologists/Managers.
  • Others – Toxicologists, Labour & safety officers, etc.
• Functions of occupational health services include:
  • Environmental monitoring & safety.
  • Industrial health education.
  • Control of workplace effluents.
  • Maintenance of medical records.
  • Social and welfare services provision.
  • Pre-employment and periodic medical examinations.
  • Factory health development and rehabilitation services.
• Principles of hazard control:
  • Complete elimination by substitution by changing the type of process.
  • Safety monitoring and health education
  • Adjunct measures and house keeping
  • Through containment by regulated time exposures and personal protection.

Occupational Cancers

• Outline
  • Definition of Occupational cancers
  • Classes or Carcinogenesis -Strategies Identification
• Cancer is a neoplasm ("new growth") that invades normal tissues and spreads (metastasises) to distant sites
  • This neoplasm results from an accumulation of hereditary mutations that control cell division
• Occupational cancer -Cancer specifically attributed to an agent* in the workplace and occurring among substantial members of workers with substantial levels of exposure
• Global burden of occupational cancers - 2-10%
  • Challenges include exposure assessment
  • Interaction- different joint effect of 2+ carcinogens are synergistic and antagonism
• Relevance of occupational cancer epidemiology-1
  • Provides a basis for compensating victims
  • Improves our understanding of carcinogenesis
  • 50% of known human carcinogens are used in workplaces
• Carcinogenesis is a multi- hit process- 80% has to do with the environment while nature related factors are just 10%
  • Cancer results from environmental carcinogens or radiation
• The timeline of development of cancer may involve 40-15 years
  • Related to exposure
  • Tumor differs from naturally occurring counterparts
• The International Agency for Research on Cancer (IARC) classifies carcinogens into 4 groups:
  • Group 1: Carcinogenic to humans (21%)
  • Group 2A: Probably carcinogenic to humans (16%)
  • Group 2B: Possibly carcinogenic to humans (63%)
• Group 3: Not classifiable
  • Group 4: Not carcinogenic to humans
• Some chemicals are occupational- Vinyl Chlorides & Aromatic Amines result in bladder cancer
• IARC Group 1, an agent that is identified as: coal gasification , Rubber industry
• Group 2A are identified as those occupational such cobalt and petroleum refining -Discovering occupational carcinogens Epidemiological and Experimental Surveys
• Primary cancer prevention -Provide workers with PPE and monitor them constantly