Environmental Health PDF

Welcome TO ENVIRONMENTAL HEALTH PREPARED BY ABDULLAH AHMED BAMHERZ  WHO definition of Health: “Health is a state of complete physical, mental, and social well-being and not merely the absence of disease and infirmity.”  Concept of health promotion Health promotion is “a process...

Welcome TO ENVIRONMENTAL HEALTH PREPARED BY ABDULLAH AHMED BAMHERZ  WHO definition of Health: “Health is a state of complete physical, mental, and social well-being and not merely the absence of disease and infirmity.”  Concept of health promotion Health promotion is “a process of enabling people to increase control over their health.” Health promotion focuses on the social determinants of health as well as on specific health issues. HUMA N  Introduction “If you want to learn about the health of a population, look at the air they breath, the water they drink, and the places where they live.”  Introduction Environment: The circumstances, objects or conditions that surround all living organisms and that affect their development and survival.  Introduction Environmental health: is the branch of public health that: focuses on the relationships between people and their environment; promotes human health and well-being; and fosters healthy and safe communities.  Introduction Safe: “Free from harm or risk; secure from threat of danger, harm,  Introduction Risk: the chance that a person/living organism may be harmed or suffer adverse health effects if exposed to a hazard.  Introduction Hazard: A potential source of harm or adverse health effect on a person/living organism.  What is contamination and what is pollution? Contamination: Refers to the presence of a substance where it should not be or at concentrations above background.  Environmental Pollutants Environmental pollutants: Substances not normally found in the environment and that in large enough amounts produce adverse health effects. Transferred to humans and other living organisms by inhalation, ingestion, or absorption.  Environmental Factors Physical: Noise, radiation, temperature, climate,. Socioeconomic: Access to housing, education, health care. Psychosocial: Human-human interactions in living and working conditions.  Environmental Factors Environmental circumstances that affect the lives and health of living organisms. Chemical: Toxic waste, pesticides, Volatile Organic Compounds (VOCs). Biological: Pathogenic microorganisms, insects, other living organisms.  What is contamination and what is pollution? Pollution: Pollution is contamination that can result in adverse biological effects to the environment and living organisms.  Types of pollution Air Radiation Water Light Soil Noise Food Indoor Thermal Outdoor  Pollution and the environment Environmental Degradation What is affected: Air, water, soil, food, climate, atmosphere. Who is affected: All living organisms: humans, animals, plants, microorganisms.  Pollution and the environment What are some of the effects: Disease development. Disruption of reproduction and lifecycles in living organisms. Climate changes. Damage to the ozone layer.  Effect of pollution on human health Environmental Diseases: Illnesses and conditions caused by factors in the environment. Chronic diseases. Man-made pollutants, natural pollutants, or changes in environmental conditions.  Effect of pollution on human health Factors: Factors that affect the development of environmental diseases: The type of pollutant. The amount of pollutant. The length of exposure to the pollutant. The genetic makeup of the individual exposed to the pollutant.  Some Human Environmental Diseases Lung diseases. Nervous system disorders. Cancers –thyroid, skin, lung, leukemia. Chronic fatigue. Immunodeficiency Heavy metal poisoning. disorders. Reproductive disorders. Gastrointestinal diseases. Environmental quality and disease burden worldwide Poor environmental quality, diarrheal diseases and respiratory infections are among the leading illnesses worldwide. Children are at a greater risk from environmental hazards, including polluted water and air (WHO).  Environmental quality and disease burden worldwide Main issues related to poor environmental quality: Unclean water and diarrheal diseases. Cholera, dysentery, guinea worm, typhoid, and intestinal worms. Waste water discharge into rivers, lakes and oceans. Indoor air pollution as a cause of death in children. Pneumonia and other respiratory infections caused or worsened by use of solid fuels such as wood, coal. Smoke with high content of small particulate solids.  Chemical contaminants Air contaminants: Can be gases, liquids or solids. 1-Gases and vapors: form true solutions in the air and cannot be distinguished from the air. 2-Aerosols: dispersions of solid or liquid particles in the air. The characteristics of the particles affect their ability to stay in the air and to scatter light. Size, shape, volume and density.  Chemical contaminants Water contaminants: Gases: Oxygen is the most important gas for water quality and to sustain aquatic life. Gases like hydrogen sulfide (HS2) or ammonia (NH3), are usually the product of decay processes, and are toxicants.  Chemical contaminants Solids: can be dissolved or suspended. Dissolved natural mineral salts like sodium chloride are not considered contaminants. Suspended solids can dissolve, grow, coagulate or be ingested by aquatic life. They may “float”, be part of an oil film, or fall to the bottom to become sediments. Not all suspended solids are contaminants.  Chemical contaminants Food contaminants: Can enter the food during production, harvesting, processing, packaging, transportation, storage, cooking, and serving. Natural or man-made. Physical, chemical or biological.  Chemical contaminants Toxic compounds can enter a food or form within a food by chemical reactions with other food components or additives, or by thermal or microbiological conversion reactions during processing, storage or handling.  Human exposure to chemical contaminants Inhalation–the respiratory tract is the most common route of entry for chemicals into the body. Gases, dusts, mists, fumes, vapors and airborne particulate matter can be breathed in through nose or mouth and into the lungs. Human exposure to chemical contaminants Absorption–chemicals in the form of dust, smoke, liquids, gases or vapors, can enter the body through the skin or eyes. Ingestion–hazardous chemicals that enter the body through the mouth, in the form of dust, particles or mists –inhaled of swallowed. Injection–not a common route of entry. Chemicals can enter the body through an accidental impact, cut or puncture to the skin.  Human exposure to chemical contaminants Effects of exposure can happen Directly at the site of exposure (respiratory tract, digestive tract, skin). In any organ after diffusion or transport by blood or lymph.  Human exposure to chemical contaminants Many chemicals are common in the environment at very low doses. Air, water, soil, food, indoor/outdoor.  Chemical exposure and health (1) The amount of the toxic substance absorbed, inhaled or ingested. (2) The fraction of the toxic material transferred across epithelial membranes of the skin, the respiratory tract, and the digestive tract.  Chemical exposure and health (3) The fractions transported via circulating fluids (blood, lymph)to target tissues. (4) The fraction taken up by target tissues. Thanks for your attention 35