Environment & Health

Dr. Dalia El-ShafeiAss.Prof of Community

Medicine

Environment: any things surrounding us & can affect health

Environmental sanitation: properties & requisites of clean environment.

Environmental health: protection of human health from hazards of unsanitary environment.

Definitions

Components of environmental sanitation

Proper planning of a new district or city or village before construction

1- Town planning

New city must be classified into industrial, commercial & residential zones.

Wide streets, parks, green areas

Available health services, fire extinguishing center, transportation methods.

Basic requirements of planning are:

2 -Sanitary housing

2- Sanitary housing

The health conditions that must be fulfilled in any building.

Basic requirements of sanitary building:

1. Far from industrial areas, volcanoes or river floods- quit place-clean surroundings

2. Made of safe, strong materials & proper foundations to overcome rains, destruction

3. Privacy: separate house for each family & adequate rooms in relation to individuals.

4. Adequate ventilation.5. Adequate lighting.6. Sanitary water supply.7. Sanitary waste disposal.8. Safety measures for prevention of

accidents: good lighting, safe furniture.

Question

1- State the criteria for choosing new house?

2- What are the priorities for selecting healthy house with limited resources?

Slums Narrow streets, densely populated with poor

housing & unsanitary environment.

Increased rate of infection & death Increased accidents as fire, falls

Increased social problems: addiction, crime

Psychological problems due to lack of privacy & crowdedness.

Hazards of Slum areas & Unsanitary housing

How can we solve the health problems of slum areas?

Build new towns in distant areas with all services

Low renting of houses Prevent illegal construction of houses

without sanitary water or waste disposal. Increase working chances to increase

socioeconomic status.

Urbanization Is the process of migration of people from rural to urban

areas for better opportunities of jobs, services & recreation.

Health hazards of urbanization: 1- Over crowdedness, leading to more lowering of socio

economic standard & bad sanitary conditions. (slum areas)

2- Spread of communicable diseases “TB, skin diseases, parasites, respiratory infections”.

3- Social problems, quarrel, homicides

4- Delinquency, drug abuse, more crimes.

Ventilation: providing and or removing air from a confined place by natural or artificial means.

Types of ventilation Natural ventilation artificial ventilation

3- Ventilation & air sanitation

Natural ventilation: windows, other openings of adequate area & distribution to introduce fresh air.

Artificial ventilation: air condition & fans

Quality & Quantity of components of air that can

affect health.

Air Sanitation

Causes of unsanitary air

1. Wind & air movements: dilution of substances

2. Plants & trees: give O2 & absorb CO2

(photosynthesis)3. Rains: dissolve gases &

fumes, settle down suspended dust.

Natural correction of unsanitary air

Hazards of chemical changes in air (Air pollution)

Components of air:

Introduction of one or more pollutants in the atmosphere.

Or: presence of unwanted material in air in sufficient amount & for sufficient time to interfere with comfort of man, or to

affect his health.

Def. of air pollution:

1- Respiration of man, animals & plants (O2 decreases, CO2, temp. & humidity increase, & expired air may contain

microorganisms). 2- Combustion of fuel by transportation vehicles or machines.

3- Fermentation of organic materials in refuse (CO2 increases & foul smell is produced).

4- Volcanoes & forest fires (fumes & different gases of melted metals, CO2, CO, ashes & smog after burn of trees).

5- Dust from streets, homes, & agriculture wastes. 6- EMWs from TVs & mobile telephones. 7- Excessive noise especially in cities.

8- Industrial wastes as dust, gases, fumes, & vapors.

Sources of air pollution:

They are present in the form of aerosols (solid particles or liquid droplets suspended in a gaseous medium) such as dust, pollens, smoke.

Sources: Combustion, industry.

Hazards: Reduce visibility & cause respiratory problems such as pneumoconiosis (particles less than 2.5 μm).

1- Total Suspended particulate:

It is a colorless & corrosive. It dissolves in water present in the air to form sulfuric acid.

Sources: Volcanic eruption, fuel combustion in industry. Hazards: Damaging to lungs (aggravation of CLD), plants & animals.

2- Sulfur Dioxide:

It combines with water to form nitric acid, which is responsible for atmospheric acidification (Acid rain).

Sources: High temperature combustion and action of bacteria on nitrogen containing compounds in the soil.

Hazards: Acute & chronic respiratory diseases and property destruction.

3- Nitrogen dioxides:

Carbon monoxide: It is highly toxic and results from incomplete combustion. It has great affinity for hemoglobin (Carboxy hemoglobin).

Source: Internal combustion engines. Hazard: Combine irreversibly with hemoglobin leading to asphyxia.

4- Carbon oxides:

*Carbon Dioxide: It is non-toxic in low concentration. Its increase in concentration contributes to the problem of global warming. Source: Mainly respiration but it is balanced by photosynthesis (bad effect of deforestation) and from fossil fuel combustion. Hazards: Increases earth temperature thus producing undesirable climatic changes.

It is responsible for 2/3 of all metallic air pollution.

Sources: Leaded gasoline, lead processing, smelters, paints and burning materials containing lead.

Hazards: Neurotoxin that causes mental retardation especially in children.

5- Lead:

It is formed by a 2ry atmospheric reaction driven by solar energy in the form of UV rays (photochemical reaction).

Source: It is formed in the atmosphere.

Hazard: Eye irritation and respiratory impairment.

6- Ozone:

They are volatile organic compounds that exist as gases in the air. Source: transportation & petroleum refineries.

Hazards: Some are carcinogens.

7- Hydrocarbons:

There are also minor industrial pollutants either because they are present in minor

amounts or they have minor health hazards.

Examples: asbestos, benzene, mercury, noise, odors, radiation etc.

1. Outdoor pollution (atmospheric pollution):

The wider type of pollution. It deals with an open & unlimited environment.

It affects more population, living things and property.

2. Indoor pollution: It deals with limited & mostly closed environments e.g. houses

& work environments. More hazardous than outdoor air pollution because we spent

more time inside our houses & the concentration of pollutants are much higher (much tightly closed) than in ambient air.

Other classification of air pollution according to its site:

Harmful Effects of Air Pollution Harmful Effects of Air Pollution

Air pollution is associated with a higher level of morbidity & mortality. Pollutants in air can affect mostly the respiratory system, the skin and the gastrointestinal tract.

• Exposure to air pollutants can cause or exacerbate COPD, BA, acute respiratory diseases. • It exacerbates cardiovascular problems and may even cause death in individuals with impaired coronary circulation. • Carcinogenic & mutagenic agents cause various hazards to human health e.g. malignancy & birth defects.

1- Damage to health:

Eye, nose & throat irritation Bad odor & limited visibility

Due to increase of some pollutants such as sulfur compounds, dust etc.

Sky or overhead darkening is the result of either heavy smoke or a mixture of smoke and fog in most urban areas.

2- Annoyance to senses:

Increased temperature, heavy smog cause automobile & traffic delays, poor visibility,

lethargy, poor concentration & absenteeism from various establishments.

3- Interference with production:

Metal parts of building, roofs & other metal equipment are usually damaged chiefly by corrosion from acidic compounds in polluted atmosphere (SO2 forms with water vapor H2 SO4 also hydrogen chloride reacts with water vapor to form highly corrosive droplets of Fog).

4- Property Damage:

Cracking of rubber and various forms of electrical insulation are thought to be caused by ozone (O3).

Deterioration of painted surface is caused by a variety of air contaminants.

The injury to vegetation varies from invisible injury to growth retardation of

various plants, which depend on the concentration & duration of exposure to

the toxic substance present in air as Sulfur compounds and ozone.

5- Damage to vegetation:

Greenhouse gases (CO2, water vapor, trace amounts of ozone, nitrous oxide, CFCs), act like the glass pan of a greenhouse i.e. allowing light, IR radiation and some UV rays to pass through the troposphere.

The earth surface absorbs much of this solar energy & degraded it to IR radiation (heat). Some of this heat escapes into space and some will be absorbed and trapped by the greenhouse gases and so increase the earth's temperature.

This trapping of heat is called the greenhouse effect and leads to global warming.

a) Global Warming:

Global warming

The ozone layer, the global sunscreen, is formed by the interaction of O2 with light & solar energy. Its presence in the stratosphere keeps about 99% of harmful UV rays, thus protecting man against sunburn, eye cataract, cancers and damage to immune system. It prevents much of the conversion of O2 in the troposphere to O3 which is harmful to humans. The elevation of temperature due to the greenhouse gases lead to the formation of O3 in the troposphere with all its bad effects.

b) Ozone layer perforation:

Smog is a mixture of 1ry & 2ry pollutants that forms when some of the 1ry pollutants interact under the influence of sunlight. Normally, during the day, the sun warms the air which rises up carrying pollutants away from the surface leaving a cooler layer with less concentration of pollutants. Sometimes, weather conditions trap a layer of dense cool air beneath a layer of less dense warm air, a phenomenon called thermal inversion and thus prevents ascending of pollutants away from earth.

c) Smog formation:

Due to increased emissions of SO2 & NOx from fuel combustion, acids form from their reaction with water leading to formation of acid rain. This acid rain leads to damage of plants, soil, buildings etc.

d) Acid Rain:

Air Quality Index (AQI)

The AQI is an index for reporting daily air quality.

EPA calculates the AQI for 5 major air pollutants regulated by the Clean Air Act: ground-level O3, particle pollution (particulate matter), CO, SO2, and NO2.

AQI scale is from 0 to 500. The higher the AQI value, the greater the level of air pollution and the greater the health concern. The purpose of the AQI is to help you understand what local air quality means to your health. The AQI is divided into 6 categories

Air Quality Index (AQI)

AQI values are derived from air quality data readings of pollutants affecting air quality. The index is derived using the following formula:

Air quality index (AQI) values

AQI values below 100 are generally thought of as satisfactory.

The data readings are recorded in different units of measure, depending on the type of

pollutant.

Air Quality Guide for Particle Pollution

Indoor is more hazardous due to:1- we spent most of our time indoor 90%

(house-school-office)2- high concentration of pollutants( much

tightly closed) than in ambient air.

Which is more hazardous outdoor or indoor

pollution?

Prevent health hazards Increase human comfort, production

Prevent property damage Prevent vegetation damage

Protect ozone layer Prevent global warming, climate changes.

Why we must control the air pollution

problem

1- Outdoor: Industrial control:A- adequate zoning of industries in special areas.

B- control at source level: - substitution of highly toxic by less one. - modification or changes process or equipment. - adequate house-keeping & disposal of wastes.

C- particulate removal technique: - filter removal of particles. - electrostatic precipitators.

Control of air pollution

Transport control:- control emission from car (lead free fuel).- minimize traffic load inside cities (out cities roads).

Legislation:- determine degree of pollution.- continuous monitoring of air pollution.- preservation of nature air purification (forest, trees).

Regularly ventilate houses. Test the level of pollution.

Avoid strong gasoline and solvents in houses. Grow plants in houses.

Avoid smoking in houses. Don’t use aerosols spray products.

Heater, stoves are properly installed and maintained.

In factories; workers must used masks & regularly checked for lung function

2- Indoor air pollution control

Avoid using products containing CFC Don’t use aerosol spray

Check house appliances that contain ferion such as refrigerators, freezers, air conditioners

3- Ozone layer

Start by yourself, how can you prevent the health hazards of air pollution?

Cultivation of plants, treesDecrease use of Freon, pesticidesSanitary waste disposalTransport control , decrease emission of cars

Question

Thank you