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close this bookBasic Concepts in Environment, Agriculture and Natural Resources Management: An Information Kit (IIRR, 1993, 151 p.)
close this folderPollution
View the documentToxic and hazardous wastes
View the documentPollution and long-term effects on the human body
View the documentUrban pollution: The metro Manila environment
View the documentMining operations: environmental effects on soil, water, communities and atmosphere
View the documentPesticides: environmental and health effects

Toxic and hazardous wastes

Toxic and hazardous wastes


Human activities produce wastes. These wastes accumulate in amounts that may harm the environment and, at sufficiently high concentration, have undesirable effects on plants, animals and man. For example, mining processes contribute heavy metals which may be leached from exposed ores and. waste rocks such as iron, copper, mercury and lead. Factories which change raw materials to finished products produce large amounts of waste products. Industrial operations emit air pollutants like carbon monoxide, oxides of nitrogen, hydrocarbon and lead.

Damage to human health

Examples of toxic wastes affecting human health are numerous:

· Recently, just as the tong-term effects of mercury poisoning in Davao del Norte are being known, disturbing reports indicate that mercury poisoning is spreading to other parts of gold-rush Mindanao.

· In Metro Manila, a World Health Organization (WHO) study revealed that Metro Manilans are exposed to at least 10 times more lead in the air than WHO-prescribed standards. Lead mainly affects the central nervous system, causing fatigue, headache, tremors and convulsion.

· The Department of Agriculture warned residents of Monkayo, Davao del Norte, against eating the meat of animals suspected to have died after drinking from polluted bodies of water. Petrochemical analysis from the Bureau of Mines reported heavy traces of cyanide in water samples.

Important issues


So little is known about the health effects of hazardous wastes that setting exposure levels, in efforts to protect human health, often proves ineffective. Substances coming from wastes vary in their toxicities and produce different toxic effects. This is because they differ in the kinds of chemical reaction they undergo within the biochemical systems. For example, metallic mercury (Hg) is not poisonous. Ingestion of small amounts of mercury, as from a bit of silver amalgam a dentist uses to fill a cavity, is not considered a hazard. But, while metallic mercury is not toxic, its vapors are. Inhalation of enough mercury over a period of time affects the central nervous system, producing symptoms of insanity.

Hazardous Waste Management

Sound management of hazardous wastes is a goal not yet achieved in many countries, even developed ones. Many of the recommended/common ways of waste disposal have been proven to be ineffective and some even pose further hazards. For example, the sanitary landfill has been generally adopted as a substitute for open dumping and burning. Yet, it has been found that, in a sanitary landfill, there is a danger that explosive methane gas and toxic hydrogen sulfide gas, produced by anaerobic decomposition, can build up and explode.

Lack of Data

The lack of data on hazardous waste generation and its effects on health and environment continues to be a major stumbling block, thus hampering proper regulation.

Toxic and dangerous substances and materials that require priority consideration

Arsenic and compounds
Mercury and compounds
Cadmium and compounds
Thailium and compounds
Beryllium and compounds
Chromium(VI) compounds
Lead and compounds
Antimony and compounds
Phenolic compounds
Cyanide compounds
Organohalogenated compounds, excluding inert polymeric materials
Chlorinated solvents
Biocides and phytopharmaceutical substances
Tarry materials from refining and tar residues from distilling
Pharmaceutical compounds
Peroxides, chlorates, perchlorates and azides
Chemical laboratory materials
Selenium and compounds
Tellerium and compounds
Polycyclic aromatic hydrocarbons
Metal carbonyls
Soluble copper compounds
Acids and/or basic substances used in the surface treatment and finishing of metals
Organochlorines (e.g.,PCBs,DDT)

Pollution and long-term effects on the human body

Parts of the body affected by various pollutants


Many different kinds of pollutants affect the human body unknowingly because the chronic (months to years of exposure to the pollutants) are not dramatic compared to the acute (few seconds to days exposure) menaces. The more pronounced acute symptoms are diarrhea, eye and skin irritation, cough and sneezing. Often, by the time clinical symptoms (months to years of exposure to the pollutants) emerge, permanent damage has already been done. Pollutants may also affect the unborn child of a pregnant mother. The effects may appear as abortion, stillbirth and congenital birth defects.

Some pollutants, its long-term effects and the specific organs affected are presented below.



Organs Affected/Effects


Lead battery manufacture


Paint/Smelting industry

Impairment of learning and intelligence in school children

Ingestion of crayons containing lead pigment

Lead encephalopathy (damaged to brain tissue)

Chewing of toys with paint

Mental retardation

Leaded gasoline

Digestive system

Persistent abdominal pain


Bloody urine


Damage to the formation of hemoglobin; joint pains; anemia



Gold extraction from mineral ores


Electrical contacts and vapor lamps

Tremor, loss of memory, lack of, confidence, vague fears and depression


Bloody urine

Oral cavity

Gingivitis (infection of the gums)


Pesticides containing arsenic


Copper smelting

Chronic irritation of the skin

Digestive system

Persistent abdominal cramps, nausea

and vomiting (simple attack)


Chronic irritation/permanent

impairment of vision

Irritant Gases/Asphyxiants

Fumes from smoke-belching cars; emissions from


Sulfur dioxide

industries; cigarette smoke

Aggravation of cardiovascular illnesses


Coal gas industry


Sulfide (H2S)

Gold extraction from mineral ores

Loss of consciousness; impairment of mental function


Fertilizer industry

Aggravation of respiratory diseases (asthma, pneumonia)

Nitrogen dioxide


Carbon dioxide


Carbon monoxide

Reduction of vision

Hydrogen cyanide


Cigarette smoke and

Dusts (vegetable animal)

Cotton fibers


Coffee bean hull

Respiratory tract irritation (cough, sneezing) asthma, pneumonia

Rice hull

Sugarcane bagasse


Animal feathers



Manufacturing, packaging industry


Residues from food

Nervous disorder (paralysis); loss of consciousness

Pesticide from household use

Behavioral disorder (mental disorder)




Chronic allergy


Chest tightness/pain, chronic respiratory tract irritation

Ultraviolet radiation

Destruction of the ozone layer


Prolonged exposure to

Cancer of the skin



Eye impairment (e.g., cataract)


Anti-rust plating material


As salts used as pigments and

Chronic pulmonary irritation

coloring agents for plastics,


ceramics and glass


In nuclear reactors as


absorbing material

Hypertension (High-blood pressure)


Itai-itai disease (softening of the bone associated with pain)


Chronic kidney damage


Geothermal industry


As a component of pesticide

Chronic irritation of the nose and throat

As pigments of white paints.

Pneumonia-like symptoms

Reproductive organs


Impaired female and male

reproductive functions.

Urban pollution: The metro Manila environment

Urban pollution: The metro Manila environment

The environmental problems associated with large cities in developing countries are a result of the high density of human activities, high consumption of resources and generation of wastes and rapid unplanned growth. The combination of these forces leads to high levels of pollution, congestion, crime and health problems. Metro Manila is no exception; with 12,604 people per sq. km., it has the highest population density in the country. The lack of adequate waste disposal has created an unhealthy environment for human habitation.

Mining operations: environmental effects on soil, water, communities and atmosphere

Mining operations: environmental effects on soil, water, communities and atmosphere

Mineral Resource - Nonrenewable chemical element or compound in solid form that is used by humans. Mineral resources are classified as metallic (such as iron and tin) or nonmetallic (such as fossil fuels, sand and salt).

Philippine mineral resources include gold, copper, silver, molybdenum, chromite, iron, lead, zinc, pyrite, ore, coal, sulfur, uranium, etc. They are used in the automobile, housing and other heavy industries. It is one of the country's dollar-earning industry.

Most of the mineral resources are located in mountainous areas, near river systems that support lowland communities and coastal areas. The most common type of mining operation used in the country is the open-pit mining. Extraction of gold, copper and ore, among others


Effects on land/soil

· Mining operations necessitate the removal of green vegetation and the dumping of waste soil. Left alone, mountains will lose their natural barriers against heavy rains with cascading flood waters eroding the top soil, making the surrounding lands ill-suited for crops and trees, rendering them unproductive and lowlands will be vulnerable to flash floods.

· Large areas may be destroyed to massive excavations and removal of large volume of rocks and soil materials. Huge pits will be formed, destroying the aesthetic value of the landscape.

· Occurrences of landslides and mudflows due to the weakening of rocks, accumulation of sand and other debris in mine dams or in natural depressions may lead to great loss of life and property.

Effects on water resources

· Intensive drainage or use of surface and groundwater may cause the drying of streams or the groundwater discharge in springs or outlets of underground rivers.

· Many mineral deposits commonly contain pyrites and other sulphuric-bearing minerals which decompose in water and produce acid water.

· Small-scale gold mining operations have been responsible for mercury pollution in rivers, lakes and seas.

· Heat pollution results when hot waters are drawn to the surface, as in geothermal waters, and are then discharged into surrounding water bodies without initial cooling.

Effects on the communities

· Dumping of tailings has affected lowland populations living downstream. Mine tailings fill streams or river systems and riverbanks are periodically eroded and inundated. Settlements in relatively lowerelevations are subject to frequent flooding, large tracts of farm lands are inundated by mine tailings during typhoons or heavy rains. Tailings are devoid of Nitrogen, Potassium and Phosphorous -- soil elements necessary for normal plant growth and development. Mine tailings contain toxic substances directly inimical to sea life and indirectly to humans.

· Mine tailings caused the filling of certain bays and have been responsible for the siltation and consequent death of some coral reefs, adversely affecting the fish catch of fisherfolk.

· The accumulation of waste rocks and tailing occupies large areas formerly used for agriculture and forestry, purposes.

· Mining expansion and pollution have dislocated many people from their farms, forcing them to migrate to other areas.

Effects on air

· Pollution of the air occurs during mining, smelting and refining. Pollution takes the form of dust or total suspended particulates (TSP), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx) and hydrocarbons (HC). Toxic emissions cover large areas affecting the health of people.

· Acid rain results from the interaction between sulphur dioxide emissions from smelters fed with sulphides of copper, lead, zinc and other metals and rainwater. This type of pollution is responsible for the destruction of some crops and forests, the pollution of lakes and negative effect on the health of people.

Pesticides: environmental and health effects

Pesticides: environmental and health effects


Pesticides are any substance or mixture of substances used to prevent, destroy, repel or mitigate insects, rodents, nematodes, fungi, weeds and/or other organisms perceived to be troublesome (pest). Its use continues to be an essential and growing component of modern crop technologies. Also, there are several pesticides that are being used at the household level to repel or kill rats, mosquitoes and cockroaches.

However, pesticides pose health and environmental hazards, as has been documented. Worldwide statistics showed that there is a conservative estimate of two million cases of pesticide poisoning last year wherein four percent of this led to death. The problem of underreporting is noticeable because of the lack of knowledge and awareness on signs and symptoms of pesticide poisoning.

Unsafe, indiscriminate and irrational use of pesticides constitute the following:

· regular use of pesticides even when unnecessary;
· not wearing the appropriate protective clothing;
· improper storage, preparation, application and disposal of pesticides and used clothings; and,
· use of pesticides in cocktail or mixtures.

The effects of the indiscriminate use of pesticides can lead to ecological disruption. Among the effects are as follows:

· contamination of ground and surface waters; thus, killing aquatic life forms through runoff and seepage (environmental contamination);

· transmittal of pesticide residues through the food chain to the farm family and urban consumers (biological magnification);

· increase in the resistance of pest population to pesticides (resistance development); thereby, reducing efficacy and causing pest outbreak (pest succession);

· reduction in the population of beneficial insects (butterflies, spiders), parasites (earthworms) and predators; and,

· reduction in the population of microorganisms in the paddy soil and water that help sustain soil fertility while lowering chemical fertilizer use.

The effects of irrational and unsafe use of pesticides on health can lead to any of the following:

· acute poisoning (may occur from single exposure to the pesticide) which is manifested by skin and eye irritation, manifested as cough, colds and shortness of breath) respiratory tract irritation, systemic poisoning and, in some cases, death; and,

· chronic poisoning (results from months or years of continual exposure to pesticides) which can lead to nervous disorders (paralysis, numbness extremities, loss of consciousness), neurobehavioral effects (mental deterioration), anemia, sterility, birth defects and effects on the unborn (manifested as abortions, stillbirths). Chronic poisoning is also suspected to cause cancer of the lungs, brain, blood, digestive system and liver, as well as decreased body's immune system or defenses.

Because of the noted environmental and health effects of pesticides, there are several of them that have already been banned from the market. Among these are the famous DIRTY DOZEN which include Parathion, 2,4,5-T, Paraquat, DDT, Aldrin/Dieldrin/Endrin, Chlordimeform, Dibromochloropropane (DBCP), Chlordane/Heptachlor, HCH/Lindane, Ethylene dibromide, Camphechlor and Pentachlorophenyl (PCP). Organotins (Brestan and Aquatin) were also banned from the market recently.