EVALUATION OF BUILT ENVIRONMENT FOR PHYSICAL SUSTAINABILITY

1. Department of Home and Health Science EVALUATIONOF BUILT ENVIRONMENTFORPHYSICALSUSTAINABILITY Name : Fawad Ahmad Reg No: 16NST01040 • Roll No: B1788460 Submitted to: Ar Omer Shujaat Bhatti

2. Introduction and objective Ecology and Sustainability of Building Materials

3. List of Materials • Timber • Steel • Concrete • Glass • Brick

4. Timber Timber is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic material, a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or wood chips or fiber. Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper, and as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate.

5. Steel Steel is an alloy of iron and other elements, primarily carbon, that is widely used in construction and other applications because of its high tensile strength and low cost. Steel's base metal is iron, which is able to take on two crystalline forms (allotropic forms), body centered cubic and face centered cubic (FCC), depending on its temperature. It is the interaction of those allotropes with the alloying elements, primarily carbon, that gives steel and cast iron their range of unique properties. In the body-centred cubic arrangement, there is an iron atom in the center of each cube, and in the face-centred cubic, there is one at the center of each of the six faces of the cube. Carbon, other elements, and inclusions within iron act as hardening agents that prevent the movement of dislocations that otherwise occur in the crystal lattices of iron atoms. The carbon in typical steel alloys may contribute up to 2.1% of its weight. Varying the amount of alloying elements, their presence in the steel either as solute elements, or as precipitated phases, retards the movement of those dislocations that make iron comparatively ductile and weak, and thus controls its qualities such as the hardness, ductility, and tensile strength of the resulting steel. Steel's strength compared to pure iron is only possible at the expense of iron's ductility, of which iron has an excess. Steel was produced in bloomer furnaces for thousands of years, but its extensive use began after more efficient production methods were devised in the 17th century, with the production of blister steel and then crucible steel.

6. Concrete • Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement that hardens over time. Most concretes used are lime-based concretes such as Portland cement concrete or concretes made with other hydraulic cements, such as ciment fondu. However, asphalt concrete, which is frequently used for road surfaces, is also a type of concrete, where the cement material is bitumen, and polymer concretes are sometimes used where the cementing material is a polymer. When aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts chemically with the water and other ingredients to form a hard matrix that binds the materials together into a durable stone-like material that has many uses.Often, additives (such as pozzolans or superplasticizers) are included in the mixture to improve the physical properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials (such as rebar) embedded to provide tensile strength, yielding reinforced concrete.

7. Glass Glass is a non-crystalline amorphous solid that is often transparent and has widespread practical, technological, and decorative usage in, for example, window panes, tableware, and optoelectronics. The most familiar, and historically the oldest, types of glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. The term glass, in popular usage, is often used to refer only to this type of material, which is familiar from use as window glass and in glass bottles. Of the many silica-based glasses that exist, ordinary glazing and container glass is formed from a specific type called soda-lime glass, composed of approximately 75% silicon dioxide (SiO2), sodium oxide (Na2O) from sodium carbonate (Na2CO3), calcium oxide, also called lime (CaO), and several minor additives.

8. Brick A brick is building material used to make walls, pavements and other elements in masonry construction. Traditionally, the term brick referred to a unit composed of clay, but it is now used to denote any rectangular units laid in mortar. A brick can be composed of clay-bearing soil, sand, and lime, or concrete materials. Bricks are produced in numerous classes, types, materials, and sizes which vary with region and time period, and are produced in bulk quantities. Two basic categories of bricks are fired and non-fired bricks. Block is a similar term referring to a rectangular building unit composed of similar materials, but is usually larger than a brick. Lightweight bricks (also called lightweight blocks) are made from expanded clay aggregate. Fired bricks are one of the longest-lasting and strongest building materials, sometimes referred to as artificial stone, and have been used since circa 5000 BC. Air-dried bricks, also known as mud bricks, have a history older than fired bricks, and have an additional ingredient of a mechanical binder such as straw

9. Energy consumption in production processing and transportation • Use of energy in buildings • Energy is used in buildings for cooking, space-heating and cooling and lighting and also for productive activities. The patterns of energy use within buildings vary a great deal according to use and location. In residential buildings, urban and rural patterns tend to be very different; household income and climate have major influences both on energy sources and end-use patterns. Numerous local studies have been carried out to identify these variations. Some typical observations are: • (a) In most low-income tropical countries, a high proportion (up to 90 per cent) of the energy used in residential buildings is for cooking: water- and space-heating needs are limited, and are commonly met by heat from the cooking stoves; • (b) In rural areas, firewood commonly meets nearly all the energy needs of households: the small amount of energy needed for lighting is met by kerosene or where available, electricity; • (c) In urban areas, a mixture of fuels is used, depending on household income: poorer families mainly use biomass, but as incomes rise, fuel use rises, and a greater proportion of more convenient fuels, kerosene, LPG and electricity are used; • (d) Cooking stoves commonly have a very low energy efficiency - wood stoves commonly used in low-income countries in Africa, Asia and Latin American require annual energy consumptions in the range 9-20 GJ per capita, compared with 1-3 GJ per capita for the more efficient gas stoves used in industrialized countries (UNCHS, 1990); • (e) In areas where there is a substantial annual heating requirement, coal-burning stoves are often used in urban housing, for instance in China and Turkey. Insulation standards in such housing are frequently very poor by comparison with those of industrialized countries, and the combustion products add considerably to urban air pollution. Where district heating is used, it is often poorly controlled and hence inefficient. China bums 90 million tons of coal per year for urban heating (Tu, 1992); • (f) In areas where the primary need is for cooling, in both hot-dry and hot-humid climates, there is an increasing demand for air-conditioning in workplaces and upper-income urban households. Air-conditioning is inherently energy-intensive in relation to the cooling achieved, since the coefficient of performance is low by comparison with heating devices, and electricity is almost always used. The poor insulation and sealing of many air-conditioned spaces adds to energy demand.

10. Energy Consumption in Timber Timber is one product amongst many designers can choose from. Many of these are promoted as environmentally viable options, but few have production process as simple and low impacts as most solid timbers products. Manufacturing process generally utilize all of a log to produce a range of products with different values. However, all logs are not the same. As the production of a natural growth cycle, native forest log come in all shapes and sizes. Plantation logs have more controlled, uniform growth, but are generally smaller and the wood has different properties to non-plantation timber. In some cases, the transport of raw and processed materials consumes a significant amount of energy. Logs are harvested in forests and weight about 1 ton/m3. A large part of this is water which is removed later in the production processes. Logs are transported from the forests in trucks on the roads usually built for the purpose. As most sawmills are position near their logs supply, transport distances from the forest to the mill are usually not long. If extended distances are involved, logs are usually loaded onto trains or, if being exported, ships. As timber is produced regionally, there is an economic in incentive to sell locally as it reduces transport costs. This combined with its light weight, has consequent environmental benefits as they tend to restrict transport impacts.

11. Energy consumption in Concrete Concrete and concrete products are examples of materials which are made by combining the building materials produced in other industries. They may be made either on site as part of the construction process (e.g., in-situ concrete), in small-scale production units or in large scale factories. In all cases, the raw materials are cement, sand and aggregates and water. Sometimes steel reinforcement is also used when prefabricated components are manufactured. Concrete blocks can be manufactured at a small scale. The energy used in the process is primarily electrical energy for vibration. This is a very small proportion of the energy embodied in the cement used. Table 2.10 shows the way in which the energy requirement for an in-situ concrete mix using dense aggregates is estimated. Most of the energy required is the energy embodied in the cement used in the mix. Transport and on-site energy, which includes the energy content of the formwork used for casting the concrete are comparatively small components. Concrete blocks and light-weight aggregate blocks used in the construction industry are made from a variety of light-weight aggregates, some of which are by-products of other industries or derived from these byproducts. Sintered pfa and sintered colliery spoil aggregates are made by sintering (burning) the waste product using the residual fuel in the waste, and are thus very-low-energy aggregates. Foamed blast furnace slag and furnace clinker are also used without processing other than grading and are thus also low-energy materials.

12. Energy Consumption in Glass The case of glass is different from the other mineral materials, since its manufacture involves high-temperature kiln processes, and its energy requirement therefore puts it in the high energy category. Glass is widely used in building but, except in special projects, the total quantity used in any building is small. For a typical house it contributes less than 1 per cent to the energy requirement. Over 80 per cent of this energy is used for melting the raw materials, sand, limestone and soda ash, in furnaces where temperatures of 1450 to 1550 × C are reached. The industry tends to be based on a small number of large producers, and developing countries are substantial importers from the industrialized countries. Energy consumption in the industry in developing countries has been steadily falling. As in the metal industries, the addition of scrap glass (cullet) to the melt is one way of reducing the energy consumption (0.2 per cent for each 1 per cent increase in the cullet ratio), and glass recycling has been steadily increasing in the industrialized countries. There are other opportunities for energy reduction, for instance through better insulation of the process, through improved plant design and recovery and reuse of the waste heat from the process. These would involve additional investment in the industry, and could produce significant returns, but would make little difference to the energy requirement of buildings as a whole. Where the energy consumption of glass becomes significant is when the lifetime energy consumption of different glazing systems are being compared. The additional savings in energy resulting from the use of double or triple glazing then need to be compared with the energy cost in their manufacture.

13. Energy Consumption in Brick Burnt-clay bricks and tiles are building materials of great importance in developing countries because they can be produced from local materials using relatively simple technologies and whatever fuels are locally available. The basic raw material is clay, although sometimes admixtures are used. All technologies involve the following stages: Winning the raw materials Clay preparation Moulding Drying Firing. A great variety of technologies are used for each of these stages ranging from simple manual technologies which have been unchanged for centuries to highly sophisticated mechanized operations. In most developing countries relatively small-scale labour-intensive methods are mostly used, and it has been found that the introduction of mechanized methods, even though they may be more energy-efficient and produce bricks and tiles of higher quality, are not successful because the high capital costs lead to higher prices for the bricks than those produced by traditional producers. Thus emphasis is now being placed on ways to upgrade the techniques used by the small-scale traditional producers. The bulk of the energy used in all production processes is the kiln fuel required to fire the bricks. This can represent more than 95 per cent of the energy requirement of the entire process in cases where ambient energy is used for drying. In other cases, significant amounts of energy may be needed for drying, for mixing, moulding and handling, but these will rarely exceed 10 per cent of the total process-energy requirement.

14. Energy Consumption in Brick

15. Energy Consumption in Steel The steel industry actively manages the use of energy. Energy conservation in steelmaking is crucial to ensure then competitiveness of the industry and to minimize environmental impacts, such as greenhouse gas emissions. Steel is also essential for energy production and transmission. Steel saves energy over its many life cycles through its 100% recyclability, World crude steel production reached 1,621 million tonnes (Mt) in 2015. By 2050, steel use is projected to increase by 1.5 times that of present levels, to meet the needs of our growing population. Steel production is energy intensive. However, sophisticated energy management systems ensure efficient use and recovery of energy throughout the steelmaking process for reuse, wherever possible. Improvements in energy efficiency have led to reductions of about 60% in energy required to produce a tonne of crude steel since 1960, as demonstrated in Figure 1.

16. "Typically, embodied energy[ina building]isequivalent tofivetoten yearsofoperationalenergy." WilliamBordass,quotedin BuildingGreen Inc. (2003) • Pollution in production, use and demolition • Buildings consume a significant amount of our natural resources and have a wide range of environmental impacts. These environmental concerns are a key driver behind the sustainable design movement. Various estimates indicate that buildings use 30% of the raw materials consumed in the United States (EPA 2001). Considering what buildings are made of – steel, concrete, glass, and other energy-intensive materials – buildings have a high level of "embodied" energy. Based on lifecycle assessments, the structural and envelope material of a typical North American office building has 2 to 4 gigajoules per square meter (175 to 350 kBtu/ft2) of embodied energy (Building Green Inc. 2003). Producing these materials depletes nonrenewable resources and has environmental effects, and these impacts intensify the more frequently buildings are demolished and replaced. Building operations also contribute significantly to Environmental pollutant levels in the United States and abroad. As a whole, U.S. buildings use 36% of U.S. energy demand, 68% of the country’s electricity (more than half of which is generated from coal), and nearly 40% of U.S. natural gas consumption (DOE 2002). As a result, U.S. buildings are accountable for 48% of the nation’s SO2 emissions, 20% of the NOx, and 36% of the CO2 (DOE 2002). Buildings also produce 25% of the solid waste, use 24% of the water, create 20% of the water effluents, and occupy 15% of the land (EPA 2001). In addition, U.S. builders produce between 30 and 35 million tons of construction, renovation, and demolition waste (DOE 2002).

17. Pollution in production, use and demolition

18. Pollution in production, use and demolition

19. Renewable or non-renewable source Non-renewable resources in the construction industry Construction activity is a major user of the world's non-renewable resources. The use in the construction industry of non-renewable fossil fuels is the most serious concern, both because of the dependency of virtually all human activities on them at the present time and also because of the current rate of depletion of these fossil fuels. Yet since burning of fossil fuels also contributes to the global production of greenhouse gases, there is a double urgency about the environmental costs of fossil-fuel consumption in and through construction. Energy and fossil-fuel use in the construction industry will, therefore, be the primary focus of this chapter. However, the use by the construction industry of certain other minerals with limited reserves is also a matter of concern, and limiting their use will also be considered. Use of fossil fuels in construction The rate of increase in the global and regional rates of consumption of fossil fuels are shown in table 5. The world's commercial energy production has increased globally by 14 per cent in the last decade. In 1989, over 95 per cent of the world's commercial energy was produced by the burning of fossil fuels -oil, gas and coal - while only the remaining 5 per cent was primary electricity produced from geothermal, hydro-electric and nuclear sources. Thus, to the extent that the construction industry uses commercial energy, whether in the form of direct fossil-fuel burning or the use of electricity, it is contributing to the depletion of fossil fuels.

20. Renewable Materials Renewable materials are sustainable materials, which means, according to the Rutgers University Center for Sustainable Materials, these materials do not use up non-renewable resources. They can also be produced in high enough volume to be economically useful. Biopolymers are one such renewable material. A biopolymer is a naturally occurring polymer, such as carbohydrates and proteins. Some examples of biopolymers are cellulose, starch, collagen, soy protein and casein. These raw materials are abundant and biodegradable, and are used to make diverse products such as adhesives and cardboard. Rapidly Renewable Materials Rapidly renewable materials are plant-based materials that can be replenished within a period of 10 years or less. Bamboo and cork are rapidly renewable materials used to create flooring materials for homes and office buildings. Bamboo is commonly used instead of woods such as oak, which is a relatively slow-growing tree. Although oak is technically a renewable resource, it takes many years for an oak tree to mature compared to bamboo. Corn Plastic Polylactic acid, or PLA, is a biopolymer derived from corn. The corn is first milled to extract its dextrose, a simple sugar. The dextrose is fermented in vats, much like brewing beer, except the final product is lactic acid. This lactic acid is then converted into long-chain polymers to create PLA, which can be used to make clear food containers for the food service industry, as well as cups, lids and even bioplastic cutlery. Products made from PLA are totally renewable and can be composted. Glass Recycled glass is another renewable resource. According to the EPA, 90 percent of recycled glass gets reused to make new glass products. Recycled crushed glass, called cullet, is mixed in with raw materials to produce new glass. Cullet is less expensive than raw materials and uses less energy to melt. Recycled glass can be used to make new containers, or used as material for kitchen counters.

21. Use of non-renewable materials in construction Fortunately, most of the materials used in construction are both abundant and very widely distributed in the Earth's crust. Apart from oxygen, which is present everywhere, silicon, iron and aluminium are the most common elements in the Earth's crust, and they are the main elements used in construction activities. • Disappearing metal  • Several metals with limited known reserves are extensively used in construction. The known world reserves, annual consumption and life index of seven leading metals are shown in table 9. Calculation of reserves is problematical. It involves making assumptions both about the extent of some deposits which have not been fully surveyed, and also about the concentration and location at which the metal can profitably be extracted at today's technology. Extraction and concentrating always involves the use of energy, and thus the latter criterion also depends on energy prices. As the price of a material increases, the incentive to search for new sources is increased, and the amount of known deposits which can be economically extracted also increases - thus reserves will increase. the reserve life indices of three metals used in construction, lead, tin and zinc indicate exhaustion of global reserves within 50 years at current rates of extraction; for copper, the index is only slightly greater at 62 years. Yet as known reserves dwindle, price rises will encourage exploration for new reserves, extraction from poor-quality raw materials and a search for alternatives. Non-renewable timber species  The construction industry prefers tropical hardwoods because of their durability, color and texture. Although there are probably in excess of 10,000 different species, the vast bulk of trade, especially international trade, consists of only a few species. Table 10 shows that 60 per cent of the sawn hardwood timber imports to the United Kingdom in 1988 consisted of just seven species. An almost insignificant proportion of the tropical rainforest from which these species are obtained is being managed sustainably, and consequently many of these species (and a long list of other species which are traded internationally) are nearing commercial extinction. Tropical hardwood, therefore, must be regarded as non-renewable materials.

22. Potential for re-use/recycling Concrete: The value of in situ concrete in terms of recycling is low. It can, however, be crushed and ground to aggregate. The majority has to besotted and used as landfill. In theory, steel can also be recycled from reinforcement, though this is a complex process using machines for crushing the concrete, electromagnets for separating, etc. Until 1950, smooth circular steel bars were used which were much easier to remove from concrete. Fiber reinforcement has no recycling potential. Constructions consisting of prefabricated components such as blocks and slabs have considerably better recycling possibilities. By using mechanical fixings or mortar joints that make easy dismantling possible, the whole component can be re-used. The mortar used for construction with concrete blocks is usually produced with strong Portland cement. The construction is, therefore, very difficult to disassemble without destroying the blocks. Alternatives are the different lime mortars, mainly based on hydraulic lime. In some cases, weaker mortar may require compensation in terms of reinforcement. The end connections of larger concrete units like slabs, beams and columns are usually grouted. Floor slabs are often covered with a concrete topping or a cement screed. These constructions should be avoided and substituted with bolted connections, which make dismantling a lot easier without the risk of damaging the elements Brick: In theory, the lifespan of bricks is at least 1000 years (Gielen, 1997); if re-used it can thus serve many generations of buildings. This well justifies its high energy consumption and emissions of carbon dioxide and other effluents during production. Historically brick has often been recycled, as by the Anglo-Saxons who did not manufacture brick themselves but systematically reused the distinctive large flat bricks left by the Romans. Similarly with the dissolution of monasteries during the Reformation, many churches and religious buildings were used as ‘quarries’ for bricks and building stones, which were re-used on a large scale. Around 1935, strong mortars containing a large proportion of Portland cement became common, making it far more difficult to recycle modern walls. To recycle brick the mortar has to be weaker than the brick, or the brick will easily break. Lime mortars, including where necessary a maximum of 35% Portland cement, make it much easier to dismantle a construction made in brick masonry.

23. Potential for re-use/recycling • Glass: There are three main operations involved in the recycling of glass generated by construction and demolition: • Dismantling: the glass is removed from the building and sorted by type according to the proposed end use. • Cullet processing: only limited quantities of Construction and Demolition glass are recycled as in most countries there is no standardized system for dismantling and collection. • Shredding: the whole building is demolished and the C & D waste (including glass) is crushed and shredded into pieces. • Steel: Steel is 100% recyclable and is highly recycled. In the UK, the overall average end-of-life recovery rate for steel from buildings has been estimated from surveys to be 96% It is important to remember that this is true recycling; every tonne of scrap recovered substitutes one tonne of primary steelmaking and this can happen again and again, with existing technology and without any degradation in terms of properties or performance. Since steel was first mass produced in the 1880s it has always been highly recycled. Principally because: Steel has a relatively high economic value - the price paid for UK scrap structural steel in 2016 was around £90 per tonne .The versatility of steel means that it can be easily recycled or remanufactured into new applications as demand dictates Steel’s magnetic properties mean that it can be efficiently segregated from mixed waste streams. Timber: Timber recycling or wood recycling is the process of turning waste timber into usable products. Recycling timber is a practice that was popularized in the early 1990s as issues such as deforestation and climate change prompted both timber suppliers and consumers to turn to a more sustainable timber source. Recycling timber is the environmentally friendliest form of timber production and is very common in countries such as Australia and New Zealand where supplies of old wooden structures are plentiful. Timber can be chipped down into wood chips which can be used to power homes or power plants. Recycling timber has become popular due to its image as an environmentally friendly product. Common belief among consumers is that by purchasing recycled wood, the demand for "green timber" will fall and ultimately benefit the environment. Greenpeace also view recycled timber as an environmentally friendly product, citing it as the most preferable timber source on their website. The arrival of recycled timber as a construction product has been important in both raising industry and consumer awareness towards deforestation and promoting timber mills to adopt more environmentally friendly practices. Recycled timber most commonly comes from old buildings, bridges and wharfs, where it is carefully stripped out and put aside by demolishers.

24. Health hazards in production and use The materials delivered or supplied to site derive from a range of enterprises, operating at different scales, levels of technology and types of operation. Each type of material and production technology has its own characteristic health hazards. Many building materials industries derive their raw materials from quarrying or mining of minerals, in which workers are exposed to risks from blasting and rockfalls, and to dusts which can give rise to a variety of lung and respiratory disorders. • Cement Dust • Hazard: Exposure to cement dust can irritate eyes, nose, throat and the upper respiratory system. Skin contact may result in moderate irritation to thickening/cracking of skin to severe skin damage from chemical burns. Silica exposure can lead to lung injuries including silicosis and lung cancer. • Solutions: • Rinse eyes with water if they come into contact with cement dust and consult a physician. • Use soap and water to wash off dust to avoid skin damage. • Wear a P-, N- or R-95 respirator to minimize inhalation of cement dust. • Eat and drink only in dust-free areas to avoid ingesting cement dust. • Wet Concrete • Hazard: Exposure to wet concrete can result in skin irritation or even first-, second- or third-degree chemical burns. Compounds such as hexavalent chromium may also be harmful. • Solutions: • Wear alkali-resistant gloves, coveralls with long sleeves and full-length pants, waterproof boots and eye protection. • Wash contaminated skin areas with cold, running water as soon as possible. • Rinse eyes splashed with wet concrete with water for at least 15 minutes and then go to the hospital for further treatment. • Machine Guarding • Hazard: Unguarded machinery used in the manufacturing process can lead to worker injuries. • Solutions: • Maintain conveyor belt systems to avoid jamming and use care in clearing jams. • Ensure that guards are in place to protect workers using mixers, block makers, cubers and metalworking machinery such as rebar benders, cutters and cage rollers. • Establish and follow effective lockout/tagout procedures when servicing equipment. • Be sure appropriate guards are in place on power tools before using them. • Falling Objects • Hazard: Workers may be hit by falling objects from conveyor belt systems, elevators or concrete block stacking equipment. • Solutions: • Avoid working beneath cuber elevators, conveyor belts and stacker/destacker machinery. • Stack and store materials properly to limit the risk of falling objects. • Wear eye protection when chipping and cleaning forms, products or mixers.

25. Falling Objects • Hazard: Workers may be hit by falling objects from conveyor belt systems, elevators or concrete block stacking equipment. • Solutions: • Avoid working beneath cuber elevators, conveyor belts and stacker/destacker machinery. • Stack and store materials properly to limit the risk of falling objects. • Wear eye protection when chipping and cleaning forms, products or mixers. • Poor Ergonomics • Hazard: Improper lifting, awkward postures and repetitive motions can lead to sprains, strains and other musculoskeletal disorders. • Solutions: • Use hand trucks or forklifts when possible. • Lift properly and get a coworker to help if a product is too heavy. • Avoid twisting while carrying a load. Shift your feet and take small steps in the direction you want to turn. • Keep floors clear to avoid slipping and tripping hazards. • Avoid working in awkward postures. • Vehicles • Hazard: Poorly maintained or improperly handled vehicles can lead to crushing injuries at the plant site or other injuries for truck drivers. • Solutions: • Make sure back-up alarms on all vehicles are functioning. • Avoid overloading cranes and hoists. • Use care with the load out chute on concrete mixers to avoid injuries to hands and fingers. • Beware of hot surfaces on equipment and truck components. • Guard eyes against splashes of aggregate materials during loading and unloading. • Use hearing protection if needed to guard against excessive noise exposure during cement loading/unloading and while using pneumatic chippers inside truck mixer drums. • Confined Spaces • Hazard: Mixers and ready-mix trucks have confined spaces that pose safety risks for workers. • Solutions: • Follow established procedures for confined space entry and work to assure safety. • Guard against heat stress when cleaning truck mixer drums. • Wear appropriate protective equipment to avoid silica exposure when removing concrete residues from inside truck mixer drums. • Other Hazards • Welding operations can lead to flash burns. • Makeshift ladders, platforms and stairs with improper or no guardrails make falls more likely. • Workers can also be injured by falling concrete forms if the forms are improperly chocked, braced or cribbed.

26. Timber: Sources and health implications: Generally timber present no health hazards in itself. On the other hand, inhalable particulate size may possess toxic, immunological and carcinogenic properties . Respirable dust of any kind can irritate the respiratory system or interfere with mucociliary action; a number of woods are irritants of the skin (e.g. iroko, keruig, afromosia), the respiratory track (e.g., beech, iroko, maple) or the eyes (e.g. yew, tak, satinwood). Some such western red cedar, iroko and mahogany, cause allergic asthma. Other woods are poisonous (e.g. yew and oleander) such that can cause nausea and malaise and affect the heart Acording to IARC, wood dust is carcinogenic to humans . Woods directly implicated are beech, oak, and redwood . Furthermore, large quantities of airborne wood dust in an enclosed spare can cause an explosion, and some wood dust will spontaneously combust on contact with certain oils or chemicals. Acceptable exposure levels In UK, all hard wood dusts have a Maximum Exposure Limit (MEL) of 5 mg/m3, however this is considered to be totally inadequate as the mucociliary escalator, the throats’ natural defence is severely impaired at 2 mg/m3. Dust levels must therefore be kept as low as possible . Mitigation strategies: Protection of employees in the workplace is of a high priority mitigation measure. The work system must control dust from wood to ensure dust levels are below the MEL. Housekeeping methods must keep workshops free from dust, and dust must be disposed of safely. In a factory or joinery shop, permanent mechanical ventilation should be installed. On a construction site or temporary workplace, cutting in the open air will reduce dust problems but not solve them. Portable dust extractors could be of much assistance. Respiratory protective equipment should also be used. Substitute Materials All types of wood which have been proved carcinogenic should be substituted with safe species. Factors influencing exposure: People most at risk are those exposed to high levels of dust during the sanding and machining processes during production. Though construction workers are less exposed to wood dust hazards compared to carpenters, joiners and factory workers, on site fitting with equipment that lacks the dust retention features available in factories may present a hazard. On site sanding processes also offers opportunities for heavy dust exposure

27. Earthen and traditional materials Sources and health implications: House design and the choice of building materials have a strong influence on the spread of a wide range of infectious human diseases. Although it is the vectors which they can harbor rather than the materials themselves which are responsible for the diseases, in many cases selection and treatment of the materials are central to the programmed of control (53).The environment in and around dwellings provides an attractive habitat for a wide range of arthropods in that they provide shelter from climatic extremes, shade, stability, and an abundant source of food. A number of these arthropods are vectors of human diseases’ pathogens. They include houseflies and cockroaches, triatomine bugs, and domestic ticks, bedbugs and house dust mites. Some colonise humans and animals directly, while others breed outside the house but enter it to feed (54).The most important disease carried by vectors is perhaps the American form of Trypanosomiasis, or Chagas’ disease, which is transmitted by the bites of the triatomine bug. There are around 13 to 15 million people in Latin America infected by this debilitating disease with about 100 million at risk (30). The disease is caused by a parasite TrypanosomaCruzi, that can be carried in the bugs’ faeces. The faeces are deposited where the bug feeds, and the parasite can then get into the victim’s blood stream through the bite injury. The parasite lives and reproduces inside the human body, particularly the heart. People inflicted with the Chagas’ disease are often unable to work because of the damage to their cardiovascular system. Health effects of other arthropods include: plague and typhus (fleas); shigellosis, salmonellosis, and viruses - hepatitis A and poliomyelitis (cockroaches); relapsing fever (soft ticks); viral hepatitis B (bed bugs); and house dust allergy (dust mites) (54). IARC has evaluated hepatitis B virus (chronic infection with) as carcinogenic to humans, group 1. Factors influencing exposure: Research has indicated that the type of building materials used has an important influence on the spread of diseases. In a rural housing study carried out in Venezuela, for example, 200 traditional houses of mud and wattle were compared with the same number of newer houses made of concrete blocks. It was found that while 55 per cent of the traditional houses revealed the presence of triatomine bugs, they were present in only 9 per cent of the newer houses (55). Generally, where the dwelling is made from low-strength masonry in the form of unstabilised earth blocks, rammed earth or stone in earth mortar, or of mud and wattle, the walls are very prone to cracking as the earth dries, providing suitable dark spaces for disease vectors to hide. Plastered walls are less prone, as long as the plaster is maintained uncracked. Soil floors can also be a source of suitable cracks. Roofs made from palm thatch are also a problem as thatch provides plentiful hiding spaces. In Venezuela it has also been found that the eggs of the Chagas’ disease vector are often stuck to the palm fronds used for thatching. Traditional flat roofs of poles piled with brushwood and covered in a thick layer of mud are used in upland areas of Argentina and Bolivia where nights are cool. These also have been found to provide an ideal habitat for triatomine bugs (54). Furthermore, the diseases associated with these arthropods are particularly prevalent in tropical areas, since higher temperatures enable the disease vectors to breed more rapidly.

28. Substitute materials: Replacement of traditional earth and thatch materials with denser, more stable materials is often advocated as the best means to eliminate pest infestation. The least cost alternatives to earth or stone based walls most widely available are either fired brick or concrete block laid in cement mortar. Thatch roofs can be replaced by corrugated galvanised iron sheets. These materials are being very widely adopted in any case, particularly in urban areas. But using them is by itself no guarantee of protection against pest infestation, unless the building is well-built. And selection of these materials has considerable implications beyond disease control: it is much more difficult to maintain comfortable living conditions without using ceilings (which may, if used, negate all the benefits by providing new pest habitats); the cost of these materials is often prohibitive, leading to smaller built space and consequently overcrowding; and cement and fired clay manufacture are heavy users of commercial energy contributing to urban and atmospheric pollution (58). Alternative lower cost and lower-energy materials are becoming available which could provide a solution - stabilised soil for floors and walling materials, and fibre concrete tiles for roofing, making use of local vegetable fibres. Extensive trials of these materials have been conducted in different countries in recent years, and low-cost equipment is now available to enable them to be produced at low cost in small scale operations and with minimal use of commercial energy or factory-made additives (59, 60, 61). Caution should, however, be made that substitute materials could have their own health risks. For example the substitution of traditional roofing and walling materials to cement based and clay fired products still exposes those involved in their production to harmful effects of dusts and gases. In Tanzania, for example, all the 15 dust samples which were collected in three factories (a ceramic factory, a cement factory, and a kaolin quarry) indicated that the quartz content exceeded the acceptable threshold limit value of 0.1 mg/m3 thus suggesting that the exposed workers had a high risk of developing silicosis Mitigation strategies: Methods Available to eliminate infestation include spraying the walls and roofs with insecticides (however it should be noted that use of insecticides to eliminate infestation gives problems associated with insecticides); plastering walls with smooth materials; and replacing wall and roof materials with smooth crack free materials. Spraying campaigns have had some success, but where the surface of the wall is absorbent, as is often the case with unstabilised mud walls, the absorbency can reduce the surface amount of the active ingredient to which the insects are exposed to the point at which it is ineffective (56). Spraying also needs to be repeated frequently to be effective. This option may not be feasible to the poor population of the developing countries since the prices of insecticides are beyond their reach. An alternative and effective method of eliminating infestation is through the application of a smooth, durable plaster layer. One study from Brazil reports complete elimination of triatomine bugs largely due to the use of kaolin clay to produce strong smooth walls resistant to cracking (57). But the choice of materials for plastering which are compatible with earthen base materials is difficult. Cement-based plasters rarely adhere to mud walls because of the differential moisture movement.

30. Causal agents of disease encountered in buildings

31. Suggest alternate choices for non-environment friendly materials Concrete is a material that quite literally holds our cities together. From homes and apartment buildings to bridges, viaducts, and sidewalks, this ubiquitous gray material's importance to modern urban life is undeniable. But you might have heard that it also has a dirty secret: the production of commercial concrete materials releases tons of the greenhouse gas carbon dioxide (CO2) into the atmosphere each year, contributing to the calamity that is climate change. But it doesn't have to be that way. We have collated 11 green building materials that offer alternatives to concrete, and a lower environmental impact 1. Straw Bales Rather than relying on new research and technology, straw bale building hearkens back to the days when homes were built from natural, locally-occurring materials. Straw bales are used to create a home’s walls inside of a frame, replacing other building materials such as concrete, wood, gypsum, plaster, fiberglass, or stone. When properly sealed, straw bales naturally provide very high levels of insulation for a hot or cold climate, and are not only affordable but sustainable as straw is a rapidly renewable resource. 2. Grasscrete As its name might indicate, grasscrete is a method of laying concrete flooring, walkways, sidewalks, and driveways in such a manner that there are open patterns allowing grass or other flora to grow. While this provides the benefit of reducing concrete usage overall, there’s also another important perk — improved storm water absorption and drainage.

32. 3. Rammed Earth What’s more natural than the dirt under your feet? In fact, walls that have a similar feel to concrete can actually be created with nothing more than dirt tamped down very tightly in wooden forms. Rammed earth is a technology that has been used by human civilization for thousands of years, and can last a very long time. Modern rammed earth buildings can be made safer by use of rebar or bamboo, and mechanical tampers reduce the amount of labor required to create sturdy walls. 4. HempCrete HempCrete is just what it sounds like – a concrete like material created from the woody inner fibers of the hemp plant. The hemp fibers are bound with lime to create concrete-like shapes that are strong and light. HempCrete blocks are super-lightweight, which can also dramatically reduce the energy used to transport the blocks, and hemp itself is a fast-growing, renewable resource.

33. 5. Bamboo Bamboo might seem trendy, but it has actually been a locally-sourced building material in some regions of the world for millennia. What makes bamboo such a promising building material for modern buildings is its combination of tensile strength, light weight, and fast-growing renewable nature. Used for framing buildings and shelters, bamboo can replace expensive and heavy imported materials and provide an alternative to concrete and rebar construction, especially in difficult-to reach areas, post-disaster rebuilding, and low-income areas with access to natural locally-sourced bamboo. 6. Recycled Plastic Instead of mining, extracting, and milling new components, researchers are creating concrete that includes ground up recycled plastics and trash, which not only reduces greenhouse gas emissions, but reduces weight and provides a new use for landfill-clogging plastic waste.

34. 7. Wood Plain old wood still retains many advantages over more industrial building materials like concrete or steel. Not only do trees absorb CO2 as they grow, they require much less energy-intensive methods to process into construction products. Properly managed forests are also renewable and can ensure a biodiversity habitat. 8. Mycelium Mycelium is a crazy futuristic building material that’s actually totally natural – it comprises the root structure of fungi and mushrooms. Mycelium can be encouraged to grow around a composite of other natural materials, like ground up straw, in molds or forms, then air-dried to create lightweight and strong bricks or other shapes.

35. 9. Ferrock Ferrock is a new material being researched that uses recycled materials including steel dust from the steel industry to create a concrete-like building material that is even stronger than concrete. What’s more, this unique material actually absorbs and traps carbon dioxide as part of its drying and hardening process – making it not only less CO2 intensive than traditional concrete, but actually carbon neutral. 10. Ash Crete Ash Crete is a concrete alternative that uses fly ash instead of traditional cement.  By using fly ash, a by-product of burning coal, 97 percent of traditional components in concrete can be replaced with recycled material. 11. Timber Crete Timber rete is an interesting building material made of sawdust and concrete mixed together. Since it is lighter than concrete, it reduces transportation emissions, and the sawdust both reuses a waste product and replaces some of the energy-intensive components of traditional concrete. Timber Crete can be formed into traditional shapes such as blocks, bricks, and pavers.

36. Conclusions The results provided approximations of the real environmental impacts of building materials. They suggest that making roof tiles out of concrete is a better option than using either ceramic or fibre cement roof materials: although ceramic tiles are better than fibre cement roof tiles in that they could save 60 per cent more primary energy, concrete Tiles are better again in that they could save 42 per cent primary energy compared with ceramic roof tiles. In addition, it is preferable to use quarry tiles instead of ceramic tiles in flooring: quarry tiles may provide an 86 per cent saving in primary energy and a possible 66 per cent saving in emissions. For bricks, local clays and renewable constituents, such as straw, had lower environmental impacts compared with conventional bricks. Replacing synthetic insulation materials, such as polyurethane rigid foam and EPS (expanded polystyrene), with natural insulation materials, such as cork, wood fibre and sheep’s wool, also appeared to reduce environmental impact. For example, production of polyurethane places high demands on primary energy and water consumption, whilst sheep’s wool could emit 98 per cent less CO if the wool is incinerated at end-of-life. The energy-intensive manufacture of clinker (the main component of cement) is a major contributor to the environmental impact of cement products used in buildings. Switching to renewable sources of energy and improving technologies by making better use of the waste heat from the furnace or reducing the furnace temperature,

37. Conclusions for example, could halve the emissions of CO from cement manufacture by 2050. Constructing buildings with wooden structures would also lower the primary energy demand and could be almost carbon neutral, or even carbon negative if the wood was recycled and reused at the end-of-life. Other construction materials, such as steel, aluminum, copper, glass and PVC should be reused and recycled where possible to reduce the primary production of these materials. For example, producing secondary steel (e.g. using scrap steel) could reduce emissions by 74 per cent, compared with producing the same amount of primary steel. Companies should be encouraged to construct buildings that can be disassembled rather than demolished at end-oflife,to make it easier to separate materials for reuse and recycling. For example, bolts can be use instead of Adhesives to fix joints between materials. Upgrading Technologies (e.g. In kilns) and techniques (capturing And Reusing heat) and using local resources where possible can also reduce Environmental impacts. In addition,Manufacturers are urged to use EPDs (Environmental Product Declarations –ISO Type III mecolabels) that provide Standardized information based on the LCA Of the real impact of each product

38. Reference http://collections.infocollections.org/ukedu/en/d/Jh1685e/4.10.html ILO, Encyclopedia of Occupational Health and Safety, Third Edition, International Labor Office, Geneva, 1983. LHC, Toxic Treatments: Wood Preservative Hazards at Work and in the Home, London Hazards Centre, UNITED KINGDOM, 1989. UNCHS (Habitat), Report of the Executive Director, Building Materials and Health (HS/C/14/7), Nairobi, 1992. Crowther, D., Health Considerations in House Design, Martin Centre for Architectural and Urban Studies, Cambridge, UNITED KINGDOM., 1991. Crowther, D., Buildings and Health, Ph.D. Thesis, University of Cambridge, United Kingdom. 1994. IRPTC Bulletin Journal of the International Register of Potentially Toxic Chemicals (IRPTC) devoted to information on hazardous chemicals, volume 9 No. 1 June 1988. Mattison, M. L., Asbestos and Asbestos Related Diseases (revised edition), Medical Advisory Group of the Asbestos Information Centre, Widness, UNITED KINGDOM, 1987 Delaine, John, Asbestos Removal, Management and Control. Gower Publishing Company Ltd, UNITED KINGDOM, 1988. WHO, Environmental Health Criteria 53 for Asbestos and other Natural Mineral Fibres. Geneva, 1986. https://www.osha.gov/Publications/concrete_manufacturing.html http://www1.eere.energy.gov/buildings/commercial?utm_source=Commercial%2BBuildings%2Bredirect&utm_medium=BTO%2Bredirect&utm_campaign=Commercial%2BBuildings%2Bredirect?ProjectID=30 The Ecology of building Materials http://www.pcs.gov.sk.ca/BenefitsHeritageConservation http://www.geotechconsultant.com/landfill.pdf