UNIVERSITY OF THE WEST INDIES FACULTY OF ENGINEERING DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING MSc in ENVIRONMENTAL ENGINEERING ENGR 6007: AIR POLLUTION
Potential Effects and Mitigations for Air Pollution in Trinidad INDOOR AIR POLLUTION CEMENT, QUARRYING AND CONSTRUCTION INDUSTRY
NAME: FELISHA MOHAN ID #: 812000567 YEAR: 1 SEMESTER: 2
Table of Contents Indoor Air Pollution .................................................................................................................................................................................... 2 TABLE 1.1 POTENTIAL SOURCE OF INDOOR AIR POLLUTION AND ITS CORRESPONDING COMBUSTION PRODUCTS ............................................................................................................................................................................................ 3 Cement, Quarrying and Construction Industry ......................................................................................................................................... 10 CEMENT INDUSTRIES IN TRINIDAD ............................................................................................................................................ 10 QUARRYING AND CONSTRUCTION INDUSTRY IN TRINIDAD .............................................................................................. 12 A CLOSED CIRCUIT WATER MANAGEMENT SYSTEM TO RECOVER ALL WASTEWATER ............................................. 13 DUST BOSS, HIGH PRESSURE SYSTEM (TCL, HSSE, 2008). ...................................................................................................... 14 DUST SCREENS (TCL, HSSE, 2008) ................................................................................................................................................. 15 GUZZLER, VACUUM TRUCK (TCL, HSSE, 2008) ......................................................................................................................... 16 SETTLING PONDS FOR SUSPENDED PARTICLES (TCL, HSSE, 2008) ..................................................................................... 17 REFERENCES ......................................................................................................................................................................................... 18
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Indoor Air Pollution The potential causes of indoor air pollutants in Trinidad are derived from natural sources, combustion or burning and man-made sources. People are exposed to a high level of economic development especially in urban areas and spend most of their time indoors (WHO, 2008). Most of the air contaminants are trapped inside the homes and schools in these urban areas giving rise to poor indoor air quality (WHO, 2008). Indoor air pollution in Trinidad can be mainly caused by solid fuel, chemicals and new substances (formaldehyde, insecticides) and also second hand tobacco smoking (WHO, 2008). In the rural areas of Trinidad, it consists of mostly agricultural areas where Indoor Air Pollution is affected by dust and organic particles. For urban areas, where the environment is not ventilated, mites and fungal contaminants would exist in the closed indoor environments (WHO, 2008). In urban areas (Port of Spain, Chaguanas, San Fernando, industrial areas such as Point Lisas), people spend most of their time indoors where their primary exposure to air pollution comes from air inside homes and schools. The contaminants accumulate indoors after a while from second hand smoke, spraying of insecticides, accumulation of pollutants in carpets and poor air quality (Burning of the Beetham) (WHO, 2008). The potential of outdoor air pollutants affecting indoor air quality in Trinidad are open fires; combustion of unsafe fuels, coal, tyres, garbage and kerosene. Volatile organic compounds release glues, resins, polishing materials, perfumes, spray propellants and cleaning agents (WHO, 2008). The effects of formaldehyde which is mostly used in household products and can cause irritation of the eyes, nose and airways. Once the outdoor air environment is poor, the indoor environment would reflect the outdoor air quality
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(WHO, 2008). The potential causes of Indoor Air Pollution are mainly industrial or agricultural activities, treatment of industrial effluents and domestic residues, traffic, solid waste management, chemical incidents and spills (WHO, 2008). TABLE 1.1 POTENTIAL SOURCE OF INDOOR AIR POLLUTION AND ITS CORRESPONDING COMBUSTION PRODUCTS
Sources
Combustion Products
Gas stoves and appliances
Carbon monoxide (CO)
Gas and propane engines
Sulphur dioxide (SO2)
Tobacco smoke
Nitrogen compounds (NOX)
Candles and incense
Particulate matter (PM)
Mosquito coils
Particulate matter (PM) (WHO, 2008)
In Trinidad, traffic is a major issue. The outdoor air pollution results from the combustion of the fossil fuels by the industrial plants in Petrotrin and vehicles. These sources release carbon monoxide, sulphur dioxide, particulate matter, nitrogen oxides, hydrocarbons and other pollutants (WHO, 2008). Potential health effects of IAP are irritation of mucous membranes (eyes, nose, throat), cough, wheeze, chest tightness, increased allergies due to open airways, increase respiratory illnesses ( common cold, pneumonia, otitis media, traceobronchitis,
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exacerbation of asthma). Long term exposure to the indoor air pollutants causes long term effects for decrease in lung growth, impaired pulmonary function, increased lung disease and asthma attacks (WHO, 2008). Carbon monoxide is a main potential cause of IAP where combustion is incomplete. Carbon monoxide in Trinidad is released from gas, kerosene, fires, furnaces and stacks from industries, vents, vehicular exhaust and tobacco smoke (WHO, 2008). These incomplete combustion in gases cause high concentrations of CO in indoor air. Carbon monoxide can affect haemoglobin which decrease the oxygen carrying capacity. Multiple organ systems in the human body can be affected by high levels of carbon monoxide, mainly the metabolic rates, central nervous system (CNS) and the cardiovascular system. Since the gas is odorless and colourless, it has deadly effects that is not recognized until the symptoms and illness are too late to be recognized (WHO, 2008). Carbon monoxide can affect unborn babies, infants and people with anemia and heart disease. Indoor air pollution with carbon monoxide gas causes fatigue, increase chest pain for people with chronic heart disease, headaches, dizziness and weakness in healthy people (WHO, 2008). At very high levels, it causes loss of consciousness and death (Carbon monoxide poisoning). To mitigate carbon monoxide effects for IAP, ensure all fuel – burning appliances are in good working condition, check heating systems, chimneys and vents regularly, never burn charcoal indoors, never leave car running in a closed garage and use CO detectors in business areas and large buildings (WHO, 2008). For urban areas, air quality test for carbon monoxide must be done every day and all air-conditioned and ventilation system must be cleaned often to prevent dirty vents and unintentional carbon monoxide related deaths.
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Tobacco smoking is another main cause of indoor air pollution at homes and schools. Second hand smoking increases the risk of respiratory tract illness, asthma, middle ear effusions, prenatal complications, low birth weight, fire related injuries, sudden infant death syndrome (SIDS), cancers (leukemia and others) (WHO, 2008). Pesticides at homes and schools affect IAP when the high concentrations are near the floor and persistence of insecticides in carpets and soft toys (WHO, 2008). This poses a risk to young children creating a chronic toxic environment indoors. The effects are carcinogenesis, endocrine disruption and neurodevelopmental effects. To prevent indoor air pollution, different classes of pesticides are used to replace toxic and very harmful pesticides. These classes of pesticides commonly used in Trinidad for controlling insects indoors are insect repellents (DEET), citronella candles, insect sprays and mosquito coils (WHO, 2008). This affects human health by acute poisoning and allergic and other symptoms such as headache, nausea vomiting, cough, rhinitis, bronchitis, asthma and allergies. Long exposures to mosquito coil smoke can cause asthma and wheezing which has a high rate in Trinidad. Volatile organic compounds (VOC) affect indoor air pollution because it is highly toxic. VOC sources are found in household products such as paints, varnishes, wax, cosmetics, degreasing products, aerosol sprays, cleansers, disinfectants, air fresheners and fuels (WHO, 2008). The possible effects of VOC’s are mainly to human health. At high levels of exposure for a long period of time, it affects the human health. For acute effects, irritation of eyes and respiratory tract, headache, dizziness, loss of coordination, nausea, visual disorders and allergic reactions (asthma). Chronic effects are damage to liver, kidney, blood system and central nervous system and cancer in humans (WHO, 2008).
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The possible mitigations of VOC’s effects on IAP can be to use household products according to manufacturer’s directions, allow a lot of fresh air to enter indoors, dispose of the containers safely and never mix the products unless directed by the label. Indoor air quality in Trinidad can be disrupted by biological pollutants such as animal dander, dust mites, moulds, infectious agents and pollen (WHO, 2008). It is caused from water damaged surfaces and materials, humidifiers and stagnant water, water vapour from cooking and showering, air conditioned systems, mattresses, upholstered furniture and carpets and dirt. These dust mites, fungi and bacteria require an environment with moisture to multiply and grow (WHO, 2008). The permeation of rain or groundwater into a building and condensation on cold interior surfaces such as air condition systems and water coolers encouraged the proliferation of microbes. Shower bathrooms with insufficient air exchange causes moisture problems. Dust mites are present mattresses, furniture and carpets. Moulds present indoors affects humans by causing infections, allergic reactions and toxic effects. The toxic effects are activated by inhalation of the mycotoxins. In order to prevent these effects, mattress and pillows should be encased, bedding should be washed in hot water, frequent vacuuming and damp mopping, decreasing clutter and removing carpets. For animals allergens, the affect some people by causing allergic reactions, dust mites and asthma morbidity. To prevent indoor air pollution caused by animals; all animals should be removed from indoor, environment and pets should be cleaned, ventilation should be at an adequate quantity and dust and moisture should be controlled Moulds which are a frequently undetected environmental problem and occur in mostly damp areas. Moulds can affect human health by causing conjunctival and airway irritation, headaches,
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difficulty in concentrating, hypersensitivity reactions such as asthma, rhinitis, systematic infections and acute exposure associated with pulmonary haemorrhage in children. Indoor air pollution in buildings can be a major concern due to the materials used in construction and the toxic releases into the air. These building in Trinidad include homes, schools and business buildings. These pollutants would have an effect on health and performance of people at school and workplace. The effects can result in lack of ventilation, increases risk of exposure caused by heating and faulty air conditioning, sick building syndrome and illness linked to airborne contaminants in the building. The sick building syndrome may cause discomfort not related to illness, time spent inside the building, causes are unknown sources, most complaints are revealed by students or employees are leaving the building or evolved area. The possible causes of sick building syndrome are due to inadequate building design, occupant activities, remodeled buildings which differ from the original building design, chemical and biological contaminants inadequate ventilation and maintenance. The possible mitigations are removal of the pollutant source, increase the ventilation system in the building, use air cleaning devices such as filters, education and communicate with the people in the building. Radon is a radioactive gas which is released from soils and rocks (Adler, 2000). The radon gas from the soil and geological area around enters the house which acts as a vacuum sucking the radon gas inside. In Trinidad, it is present and causes the increase risk of lung cancer and alteration of DNA once the build up inside a house reaches dangerous levels. Radon can be dangerous for people at home and children at schools (Adler, 2000). The mitigation system for radon involves a gas permeable layer, plastic sheeting, sealing
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and caulking, vent pipe and junction box (WHO, 2008). The gas permeable layer, 4 inches of clean gravel is placed under the flooring system which allows the soil gas underneath the house or school to move freely (WHO, 2008). A plastic sheeting is placed on top the gravel layer and under the flooring slab in order to prevent soil gas from entering the home. In the concrete foundation floor, all the openings are sealed to reduce gas entry into the buildings (WHO, 2008). A vent pipe made up of PVC (polyvinyl chloride) pipe is installed from the gas permeable layer through the house or school building straight through the roof to vent all the radon and soil gas safely above the building (WHO, 2008). Asbestos is a fibrous material (Adler, 2000). It is very resistant and indestructible and mainly used for building materials and manufactured products. Asbestos is used for insulation and fire retardation in many buildings in Trinidad. They are found in asbestos cement, floor, roof tiles, water pipes and other materials (Adler, 2000). Once the asbestos materials are damaged, levels of asbestos increases. The asbestos has many health effects such as no acute toxicity, asbestosis due to occupational exposure and its main risk is cancer especially to children at a young age into adulthood (lung cancer) after long term exposures. When the asbestos material are deteriorating, fibers are released either during destruction or renovation of the buildings with asbestos materials (Adler, 2000). These microfibers are inhaled and it is the major route and cause for cancers such as lung cancer in Trinidad. General mitigations to reduce indoor air pollution in homes are improve stoves, use clean fuels (kerosene, gas), use venting stoves for cooking and heating, do regular maintenance for heating, cooking and cooling systems, use nonvolatile and nontoxic materials for buildings and maintain dry homes and schools (Adler, 2000).. The ventilation system must be included in the building
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design to remove pollutants utilizing the outdoor air. Air filters and ionizers are used to remove airborne particles for sickness and diseases. The gas adsorbing material are used to remove gaseous contaminants for the air in the indoor environments. These mitigations are used to prevent an illness and avoid indoor air quality problems (Adler, 2000).
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Cement, Quarrying and Construction Industry CEMENT INDUSTRIES IN TRINIDAD Cement, quarrying and construction industry in Trinidad are major harm and issue to the environment. It have the potential to cause air pollution in Trinidad. Cement is a fine, gray or white powder which is mostly made up of Cement Kiln Dust (CKD) and a byproduct of final cement product (Bhalki, 2013). These are stored as waste in pen pits and landfills. Cement industry is a major source of particulate matter, SOx, NOx and CO2 emissions and cement dust (Bhalki, 2013). The cement dust also contains heavy metals such as chromium, nickel, cobalt, lead and mercury pollutants (Bhalki, 2013). These pollutants are hazardous to the biotic environment and create a negative impact on the vegetation, ecosystem, human and animal health (Bhalki, 2013). The potential causes of air pollution from the cement industry is the cement dust during production, gaseous and particulate pollutants which enhance levels of toxic metals. The potential effects of the cement industry is mostly health and environmental effects (Bhalki, 2013). Cement dust exposure for a short period of time may not have any serious problems whereas long term exposure can cause serious irreversible damage to plants and animals (Bhalki, 2013). Dust particles dissolving onto the leaf tissues may cause the stomata in the leaves to become clogged, reduction of growth and chlorophyll, interruption of metabolism, absorption of light and diffusion of gases from the leaves. The formation of the starch in the plants would be reduced which would prevent fruits and plant growth. Cement dust can cause respiratory problems, gastrointestinal diseases, chronic impairment of lung function and chronic respiratory illnesses. The gaseous and particulate pollutants cause a great hazard for all the living organisms (Bhalki, 2013). 10
The particulate matter affects the air pollution in Trinidad Cement Industries by causing smoke, dust from the industrial processes, construction industry and plant pollen. The particulate pollution can cause acute changes in lung function, respiratory illness and aggravates chronic conditions such as asthma and bronchitis (Deborah, 1996). The increase in toxic pollutants enhance the toxic heavy metal levels which causes reduction in growth, photosynthesis ability of leaves and overall productivity of plants (Bhalki, 2013). Gaseous pollutants may contribute to the air pollution in Trinidad. The potential causes of gaseous air pollution from the cement industry in Trinidad originate from cement kilns (NOx); combustion of sulphur bearing compounds such as coal, oil, petroleum coke, procession pyrite and sulphur raw materials (SO2) and heating calcium carbonate (CO2). The cement industry is the second largest carbon dioxide emitting industry in the world (Bhalki, 2013). The potential health effects of the cement dust and gaseous pollutants affect mainly the respiratory system, gastro intestinal system, stomach, allergic reaction (interference with breathing), chronic bronchitis, Emphysema, lung cancer, tuberculosis, cough and wheezing (Bhalki, 2013).
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QUARRYING AND CONSTRUCTION INDUSTRY IN TRINIDAD Quarrying in Trinidad is done by engineering activities, extraction and processing of sand and gravel. The potential cause of air pollution in Trinidad Quarrying industry is dust. The dust occur from fugitive dust from excavation from haul road, blasting and from drilling, crushing and screening (point source). The factors that affect dust generation on site are moisture, rock quality, ambient air quality, air currents and prevailing winds (Norton and Groat, 2002). Mitigations for quarrying dust which contributes to air pollution in Trinidad is an implementation of a dust control plan, good housekeeping practices rather than control systems (TCL, HSSE, 2008).. The housekeeping techniques include water trucks, sweepers and chemical application on haul roads (TCL, HSSE, 2008). On site, vehicles need to control their speed, construction of wind breaks. Also in the cement plants, the use of dry or wet control systems need to be implemented. The dry mitigation techniques include conveyors, vacuum systems and bag houses (TCL, HSSE, 2008). These systems and techniques remove dust before the air stream outlet is releases into the atmosphere. At the dust generating sites, a wet suppression system with pressurized water sprays could be used to reduce dust in the environment (TCL, HSSE, 2008). For the quarrying facility in Mayo Quarry; a closed circuit water management system is utilized to recover all wastewater and reused to prevent pollution (TCL, HSSE, 2008).
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A CLOSED CIRCUIT WATER MANAGEMENT SYSTEM TO RECOVER ALL WASTEWATER
(TCL, HSSE, 2008).
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For cement industries in Trinidad, TCL (Trinidad Cement Limited), they implemented initiatives to mitigate dust. They use a high pressure system (Dust Boss), dust screens, GUZZLER (vacuum truck), settling ponds and electrostatic precipitator. The Dust Boss is the high pressure system which creates an ultrafine mist of water used to attract dust particles (TCL, HSSE, 2008). DUST BOSS, HIGH PRESSURE SYSTEM (TCL, HSSE, 2008).
These particles forms agglomeration which them falls to the ground or back onto the stockpile (TCL, HSSE, 2008). The dust screens traps dust and prevent it from escaping to the outside or external environment (TCL, HSSE, 2008).
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DUST SCREENS (TCL, HSSE, 2008)
The GUZZLER is a vacuum truck which cleans spilled material and it is recycled back into the manufacturing process (TCL, HSSE, 2008). This truck reduces particulate emissions which arrived from conventional cleaning methods (TCL, HSSE, 2008).
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GUZZLER, VACUUM TRUCK (TCL, HSSE, 2008)
The settling ponds collect the water run-off, allows suspended particles to settle before it exits the compound (reduction of Total Suspended Solids, TSS in effluent) (TCL, HSSE, 2008).
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SETTLING PONDS FOR SUSPENDED PARTICLES (TCL, HSSE, 2008)
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REFERENCES
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