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Pollution

Industrial Pollution in Bangladesh

Industrial pollution is an area of growing environmental concern in Bangladesh. The country still has a relatively small industrial base (including manufacturing, construction, mining and utilities)The manufacturing sub-sector accounts for about half of this contribution and it grew at a rate of 5.04% between 1972 and 1992. The growth rates of some of the important sub-sectors are shown in Figure 1.1 (Bhattacharya et al., 1995). With the growth of the ready-made garments sector, the textile sector is also growing at a high rate in recent years.

Growth rates of important industrial sectors (1972/73-1991/92)

There are increasing efforts to develop the industrial sector of the country by both stimulating the local industries and attracting foreign investors. As a result, the growth rate of the industrial sector is expected to rise. The growth rate of the manufacturing sector has been projected to be 11% for the year 2000 (World Bank, 1997). As Bangladesh attempts to attain economic development by replacing its agricultural base with industries and rural enterprises with urban centers, pollution and other environmental impacts of industries are becoming critical in development planning.

Treatment of industrial waste and effluent has so far been considered a low priority, because policy planners had a feeling of complacency that industrial pollution is still at a very low level. Due to lack of awareness as well as the absence of strong punitive actions, the practice of circulating waste and effluent into water bodies including ponds, canals, creeks and rivers still remains widespread. The serious public health hazards they create are to some extent minimized as the waste and effluents are mostly flushed out into the sea during the rainy season. But excessive localized pollution is already threatening the sustainability of the resource base and having effects on the health of people, most of who are affected or unaware or hardly have any other choices.

With the Earth Summit in Rio and the Kyoto Protocol in Japan, the 1990s have been a significant decade in reshaping conventional development thinking into sustainable development. This new trend guides us to clean up existing industries and develop new ones with minimum environmental impacts. In the process, development of recycling systems, waste exchange and industrial ecology will replace the linear industrial processes with a more circulatory structure.

Estimating industrial pollution load for Bangladesh

Industrial pollution is generated during the production of the intermediate and final goods in the form of wastes. The solid part of this waste is disposed on land and dumped in water. The liquid and gaseous parts are released in water and air with or without any treatment. Some of these pollutants are relatively harmless and naturally degradable. Others have varying degrees of persistence, and as such, may cause damage to life and property for a long time to come. A complete list of all these pollutants is nonexistent. In this study, the pollution load (in tons per year) will be estimated for a select group of air, water and land pollutants on which sufficient secondary information are available.

Major industrial pollutants
Industrial emissions pose a major threat to human health, ecosystems, and economic activity. The pollutants discussed below are the major known pollutants which are monitored in many parts of the world (the following section is adapted from Faisal et al. (2000) and Hettige et al. (2000)).

Air Pollutants
Major pollutants released into air from the industrial sector are listed below. More information on these pollutants can be found in Masters (1995), De (1989) and, Rao and Rao (1989).

Total suspended particles (TSP) and fine particulate matter (PM10)
carbon monoxide
oxides of nitrogen (NO, NO2 shown as NOx)

sulfur dioxide (SO2)
volatile organic compounds (VOC)

Total suspended particles (TSP) and fine particulate matter (PM10): Total suspended particles (TSP) are made up of particles with an aerodynamic diameter between 0.0002 and 70 micrometer. Due to very small size, these particles may remain suspended in air for a very long time and can get carried away hundreds of miles by air currents. For human health impact, particles with diameter smaller than 10 micrometer (PM10) range are of main interest. Larger particles are effectively removed in the upper respiratory system. Finer particles may enter lungs and reside there for years causing respiratory infection, cardiac disorder, bronchitis, asthma, pneumonia and emphysema. Coal miners’ black-lung disease and asbestos workers’ pulmonary fibrosis are examples of PM related occupational hazards. Some carbon-aromatic based PM is carcinogenic. High TSP concentration is injurious to plants – particulate coating on leaves inhibit plant growth.

Carbon monoxide (CO): It is produced when carbonaceous fuels are burned in less than ideal conditions. Parameters that control the amount of CO produced are: oxygen supply, flame temperature, gas residence time in the combustion chamber and mixing or turbulence. Main contributors are the vehicles (may vary between 50% - 90% in the developing countries (OECD/IEA, 1991). The rest of CO comes from factories, industries, brickfields and households during burning of fossil fuel or biomass.

In terms of exposure to CO, cab drivers, police, street vendors fall in the high-risk group. The exposure is measured in % COHb (carboxy-haemoglobin) as a percent of saturation) in human blood, where less than 2% is deemed tolerable. Symptoms at higher concentrations include: 3.5% - impaired judgment, 5% - psychomotor response time affected, 10% - dizziness, severe headache, 30% - coma and convulsions, and 50% - lethal. CO binds with haemoglobin in human blood 200 times faster than oxygen. Residence time of CO in air may vary between two to five months after which most of it gets converted to CO2 (Masterson et al., 1995).

Oxides of nitrogen (NOx): The main source is high temperature combustion in vehicles as well as in furnaces and incinerators. Nitric oxide (NO) constitutes the main part (approximately 90%) of NOx. Other forms include nitrogen dioxide (NO2), nitrogen pentoxide (NO5), hydrated NO5 and nitric acid (HNO3). NO is not harmful at the ambient level but it combines with O, OH and HC and form many harmful compounds which are generally called secondary pollutants, which causes smog and acid rain.

Photochemical smog is known to cause annoying respiratory effects such as: coughing, shortness of breath, asthma, headache, eye, nose and throat irritation and damages from ozone formation (mainly to plant tissues). Prolonged exposure even to low concentrations of smog may cause respiratory infections and bronchitis in children.

Oxides of sulfur (SOx): More than 80% of atmospheric SO2 is emitted from chemical industries, smelting operations, refineries, power stations and brickfields. Sulphur is either produced as a by-product or released due to burning of high-sulphur oil or coal. The primary damage caused by SO2 is acid rain (wet and dry deposition) which causes damages to plants and ecosystems, de-coloration of buildings and paints, corrosion of metals, weakening of organic fibre, and damage to marble, limestone and mortar structures. Acid rain caused by SO2 emission has damaged huge forest tracts in the OECD and some east European countries. It has also increased the pH level of many lakes in the Scandinavian countries beyond the tolerance level of indigenous fish species. SO2 emitted from industries and vehicles may cause smog formation in urban/industrial areas. Serious respiratory problem may occur when a high concentration of SO2 is inhaled. The infamous ‘London smog’ episode in 1952 was caused by SO2 based smog that caused death to 5,000 individual in one single week (the situation was made worse due to thermal inversion).

Volatile Organic Compounds (VOC): The term volatile organic compounds, describes a class of thousands of substances used as solvents and fragrances. VOCs are particularly important in the petrochemical and plastics industries. Human exposure to VOCs is mainly via inhalation, although some VOCs appear as contaminants in drinking water, food, and beverages. Many VOCs are suspected carcinogens. Acute effects from industrial exposures include skin reactions and central nervous system effects such as dizziness and fainting. Recently, sick-building syndrome (SBS) and multiple chemical sensitivity (MCS) have been linked to the relatively low (part per billion) concentrations of VOCs which are more typical of ambient environments. In addition, VOCs may form photochemical oxidants which have been identified as eye and lung irritants.

Water Pollutants
Biological Oxygen Demand (BOD): BOD is defined as the amount of oxygen needed by aerobic decomposers to breakdown the organic materials in a given volume of water at a certain temperature over a specified time period. BOD is caused by organic water pollutants that are oxidized by naturally-occurring micro-organisms. This 'biological oxygen demand' removes dissolved oxygen from the water and can seriously damage some fish species which have adapted to the previous dissolved oxygen level. Low levels of dissolved oxygen may enable disease causing pathogens to survive longer in water. Organic water pollutants can also accelerate the growth of algae, which will crowd out other plant species. The eventual death and decomposition of the algae is another source of oxygen depletion as well as noxious smells and unsightly scum. The most common measure for BOD is the amount of oxygen used by micro-organisms to oxidize the organic waste in a standard sample of pollutant during a five-day period (5-day BOD)

Suspended Solids (SS): Small particles of non-organic, non-toxic solids suspended in waste water will settle as sludge blankets in calm-water areas of streams and lakes. This can suffocate plant life and purifying micro-organisms, causing serious damage to aquatic ecosystems. The loss of purifying micro-organisms enables pathogens to live longer, raising the risk of disease. When organic solids are part of the sludge, their progressive decomposition will also deplete oxygen in the water and generate noxious gases.

Toxic Pollutants
Toxic Chemicals: Many chemicals in industrial emissions are poisonous to humans. These chemicals affect humans through direct contact or through inhalation and intake as food. Humans can ingest severely damaging or fatal quantities through repeated exposure, or by consuming plants or animals in which these compounds have accumulated. Toxic chemicals may cause damage to internal organs and neurological functions; can result in reproductive problems and birth defects; and can be carcinogenic. Quantities and length of exposure necessary to cause these effects vary widely. Benzene and asbestos are known carcinogens linked to leukaemia and lung cancer. Common toxic chemicals include residues of pesticides and a very large group of organic chemicals that include benzene, toluene, zylene, chloroethane and chloromethane.

Bio-accumulative Metals: In bioaccumulation, relatively low concentrations of contaminants in air, water, soil and plants become far more concentrated further up the food chain. Some metals can be converted to organic forms by bacteria, increasing the risk that they will enter the food chain. Bio-accumulative metals are particularly dangerous because they are dissipated very slowly by natural systems. They may cause both mental and physical birth defects. Metals can also become rapidly oxidized and converted to soluble form when sediment is exposed to oxygen. Some of the metals which are commonly measured and particularly dangerous are mercury, lead, arsenic, chromium, nickel, copper, zinc and cadmium.

Industrial sectors and sub-sectors

Application of IPPS requires categorization of all the polluting industries according to the ISIC code so that corresponding emission factors can be used to estimate the annual emission load. This was done using the Census of Manufacturing Industries (CMI) data of 1991 published by Bangladesh Bureau of Statistics (BBS). This data base is about 10 years old and as such, the pollution estimates will have some error. However, no major change has occurred in the number or capacity of major polluting industries such as sugar mills, pulp and paper, tanneries, cement, fertilizer and, industrial and petrochemicals in the last decade. Some sectors that might have changed include textiles (and related sub-sectors), pharmaceuticals and, ferrous and non-ferrous metal industries. However, it was not possible to conduct any primary data collection during the course of this study. Emission loads from these sectors can be updated as soon as new estimates are available on the number of people employed by these sectors.

Initially, all the sub-sectors as found in the CMI report were grouped into 79 major categories. At this stage some aggregation was needed and some sub-sectors for which no ISIC code was available were lumped with others with ISIC code. The sub-sectors without any ISIC code were typically small and the error introduced because of this is likely to be small. In the second step, these 79 categories were further grouped into 22 major sectors such as food industries, pulp and paper, tanneries and leather etc. Table 5.1 shows all the 79 sub-sectors grouped into 22 major sectors.

Pollution load were estimated for this aggregated data set separately for air, water and land pollution. Finally, the sectors were ranked based on medium wise and aggregate pollution load.

Sectors	Sub-sectors with the four digit ISIC code	ISIC Code
1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 3 3 3 3 3 3 4 5 5 5 5 6 6 6 6 7 7 7 8 9 10 11 11 12 13 13 13 14 14 15 15 16 16 17 17	Meat Products (3111) Dairy Products Preserved Fruits & Vegetables Fish Products Oils And Fats * Grain Mill Products * Bakery Products Sugar Factories & Refineries Mfg. Of Gur Confectionery Products Food Products, N.E.C. Prepared Animal Foods DISTILLED SPIRITS (Agricultural Product) Wine Industries Malt Liquors And Malt Tobacco Manufactures * Spinning, Weaving, & Finishing Textiles * Made-Up Textiles Except Appare l Knitting Mills Carpets And Rugs Cordage, Rope & Twine Spooling And Thread Bal l Textiles, N.E.C. Wearing Apparel * Tanneries And Leather Finishin g Fur Dressing And Dyeing Leather Products Footwear Sawmills & Other Wood Mills Wooden & Cane Containers; Small Cane Ware Wood & Cork Products, N.E.C.* Furniture & Fixtures, Nonmetal Pulp, Paper, & Paperboard Paper & Paperboard Containers & Boxes Pulp, Paper & Paperboard Articles Printing & Publishing * Industrial Chemicals Except Fertilizer * Fertilizers & Pesticides Synthetic Resins, Plastics Materials, & Manmade Fibers Plastics Products, N.E.C.* Paints, Varnishes, & Lacquers Drugs And Medicines * Soap, Cleaning Preps., Perfumes, & Toilet Preps. Chemical Products, N.E.C. Petroleum Refineries Misc. Petroleum & Coal Products Tires And Tube s Rubber Products, N.E.C. Pottery, China, & Earthenware Glass And Glass Products Structural Clay Products Cement, Lime, And Plaster	3111 3112 3113 3114 3115 3116 3117 3118 3119 3121 3122 3131 3132 3133 3140 3211 3212 3213 3214 3215 3219 3220 3231 3232 3233 3240 3311 3312 3319 3320 3411 3412 3419 3420 3511 3512 3513 3560 3521 3522 3523 3529 3530 3540 3551 3559 3610 3620 3691 3692

Emission to air
Emission to air was determined based on emission of TSP, SO2, NO2, CO and VOC. In terms of the total emission to air, the leader is the food industry, followed by cement, pulp and paper, and textile. The major part of the food sector comes from the sugar mills, and oil and fat sub-sectors. In this group, most of the air pollutants come from the sugar mills except VOCs that mainly come from the oil/fat factories and distilleries. Other large VOC emitters include tanneries, pharmaceuticals and metal industries. In the textile sector, only emission by spinning/weaving/finishing sub-sector was estimated as data for others sub-sectors was not available. Similarly, data on the processed leather industries is not available and estimated emission came entirely from the tanneries. According to the CMI, there were 24 small and big cement factories in the country and all of these were responsible for a high level of TSP (35%) and SO2 (11%) emission. Here, air pollution is caused during the grinding process involved in making of clinker and cement dust. One sector that appears in the top five list only once is tobacco. This sector, although relatively small, contributes about 9% of the total SO2 load.

Annual air pollution (by pollutant type) caused by the major air polluting industries are shown in Figure 5.1. Percent contribution of major air polluters (in terms of total emission to air) are shown in Figure 5.2. The total emission to air as calculated in this study is an underestimate as emission factors for a number of sectors were not available in the IPPS database.

Emission to water
Emission to water was estimated in terms of BOD and TSS. The highest BOD contributor is the pulp and paper sector, followed by the food industries. As before, sugar mills and distilleries in the food sector cause most of the emissions. The dairy sub-sector has a very high BOD emission factor but at this point due to the small size of the industry, it is not a major BOD contributor. This may change in future. Collectively, pulp and paper, and food emits 93% of the total BOD load.

In terms of TSS emission, pulp and paper tops the list, followed by pharmaceuticals and metal industries. Both ferrous and non-ferrous industries have high TSS emission factors. Other high potential TSS emitters are fertilizer factories and jewelleries. Total contribution of the jewelleries is small due to small size of the industry. Its contribution is likely to be dispersed all over the country with the largest concentration in the older part of Dhaka.

Total BOD and TSS loads for the major water polluting industries are shown in Figure 5.3. Percent contribution of the major water pollutants are shown in Figure 5.4

Annual air pollution by industrial sectors

Relative contribution to air pollution by industrial sectors

Annual water pollution by industrial sectors

Toxic metal emission

It is not surprising that the metal industry is the number one polluter of toxic metals that can cause severe health damage through direct contact and bio-accumulation. Other major polluters are the cement factories, tanneries and agrochemicals (pesticides in particular). Together, these sectors contribute nearly 75% of the total toxic metal emission. Although the estimates of total toxic metal include emissions to all media (air, water and land), most sectors emit 90% to 95% of the total load to land. The only notable exception is the pulp and paper sector, which emits about 67% of the total load to land and 30% to water. Emission to air is small for most of the sectors. The only two sectors with small but noticeable emission to air are the petroleum/refineries and the paints/varnish/lacquer.

Total toxic metal emissions and the sectors responsible are shown in Figure 5.5. Percent contribution of the major toxic metal emitters are shown in Figure 5.6.

Toxic chemicals emission

The number one toxic chemicals polluter is the tanneries and leather industry, followed by pulp and paper, pharmaceuticals, fertilizer/pesticides and industrial chemicals. In most cases, the chemicals are disposed on land as part of the solid waste, parts of which are then collected and recycled. Exceptions are the pulp and paper and cement factories – these emit most of the chemical to air. Direct emission to water appears to be small – the two significant ones are 18% by the pulp and paper, and 10% by the industrial chemicals. However, it is quite likely that a significant part of the land pollution eventually ends up in water through direct runoff and seepage. Unfortunately, no information is available on the ultimate fate of these toxic chemicals.

Toxic chemical emissions to air, water and land by various sectors are shown in Figure 5.7. Relative contribution of the sectors causing toxic chemicals are shown in Figure 5.8.

Relative contribution to water pollution by industrial sectors

Annual toxic metal pollution by industrial sectors

Relative contributions to toxic metal pollution by industrial sectors

Annual toxic chemicals pollution by industrial sectors

Relative contributions to toxic chemicals pollution by industrial sectors

The most polluting sectors
The estimates presented above are summarized in Table 5.2. This shows the top-five most polluting industries, the total pollution load per year and relative contributions of these sectors to different types of pollution.

As can be seen from Table 5.2, a few sectors repeatedly appear in the top-five list and these are clearly the most polluting industrial sectors in Bangladesh. A final list of the most polluting industries is presented in Table 5.3, where the ten most polluting sectors have been identified based on their cumulative ranks (ranks for different pollution types are added to arrive at the final rank). Note that the tenth item – petroleum/refineries does not appear in Table 5.2 but its cumulative contribution is much higher than the tobacco sector, which has been dropped from the final list.

Rank	Industrial sector	Emission tons/year)	Percent contribution	Cumulative percent
	Air pollution
1 2 3 4 5	Food industry Cement/Clay Pulp and paper Textile Tobacco	146356.06 62725.88 51963.92 39831.01 16992.22	38.7% 16.6% 13.7% 10.5% 4.5%	38.7% 55.3% 69.0% 79.5% 84.0%
	Water pollution
1 2 3 4 5	Pulp and paper Pharmaceuticals Metal Food industry Fertilizers/pesticides	91768.10 30866.72 27174.61 23403.39 12715.00	47.4% 15.9% 14.0% 12.1% 6.6%	47.4% 63.3% 77.3% 89.4% 96.0%
	Toxic metals emission
1 2 3 4 5	Metal Cement/Clay Tanneries/leather Fertilizers/pesticides Textile	1071.92 688.90 659.38 407.30 192.46	28.3% 18.2% 17.4% 10.8% 5.1%	28.3% 46.6% 64.0% 74.8% 79.8%
	Toxic chemicals emission
1 2 3 4 5	Tanneries/leather Pulp and paper Pharmaceuticals Fertilizers/pesticides Industrial chemicals	13630.55 10132.96 8362.393 8226.275 5713.782	20.6% 15.3% 12.6% 12.4% 8.6%	20.6% 35.9% 48.6% 61.0% 69.6%

Projection of emission loads for the year 2011
In the previous sections, estimates of emission into air, water and land have been presented for the year 1991-92 for which the data was available through the Census of Manufacturing Industries (CMI). However, about a decade has passed since then and it would be helpful to know how these emission loads are expected to change in the coming decade. This will provide guidance to the policy makers on the necessary course of action if they wanted to limit emission of a particular chemical or compound.

In this section, emission projections have been given for the year 2001 and 2011. For all types pollutants, linear growth factors were calculated based on the estimated emission loads for the years 1981-82 and 1991-92. These factors were then used to make projections for the years 2001 and 2011. This approach has some obvious limitations. First, the implicit assumption is that all the industrial sub-sectors will continue to grow (or shrink) at the same rate as the one that existed between 81-82 and 91-92. Time, resource and data limitations did not allow separate analysis for each sub-sector to improve the accuracy of these estimates. Another limitation is the assumption that the emission factors will remain the same over the years. For some industries this may be an acceptable assumption but for many others, newer technologies may reduce emission or may cause emission of new previously non-existing pollutants. Again, it is practically impossible to predict how these emission factors will change and therefore no attempt was made to adjust these factors. Therefore, the estimates presented in this section are only tentative estimates and should be treated carefully.

No.	Industrial sector	Rank by pollution type		Rank sum
		Air	Water
1 2 3 4 5 6 7 8 9 10	Pulp and paper Food industry* Tanneries/leather Pharmaceuticals Metal** Cement/Clay Textile Fertilizers/pesticides Industrial chemicals Petroleum/refineries	3 1 8 9 10 2 4 14 13 6	1 4 8 2 3 11 9 5 6 10	18 20 20 22 22 24 25 27 30 39
Continue.

No.	Industrial sector	Rank by pollution type		Rank sum
		Toxic Metal	Toxic Chemicals
1 2 3 4 5 6 7 8 9 10	Pulp and paper Food industry* Tanneries/leather Pharmaceuticals Metal** Cement/Clay Textile Fertilizers/pesticides Industrial chemicals Petroleum/refineries	12 9 3 8 1 2 5 4 6 13	2 6 1 3 8 9 7 4 5 10	18 20 20 22 22 24 25 27 30 39

Emission into air

Emission into Water

Emission of toxic chemicals and metals

Emission of toxic chemicals is expected to increase with the growing industrialization in the country. The projection is shown in Figure 5.11. Most of the toxic chemicals will be discharged to air - about 81% of the total in the year 2011. The rest will be mostly dumped on land (19%) with a small fraction (1%) will go to water.

Emission of toxic metals

Almost all of the toxic metal emission will end up on land – about 97% of the total load in 2011. The rest will go to land (2%) and water (1%). This is true for individual industries except the pulp and paper sub-sector that dumps the major part of its toxic metal load in water. Overall, the total toxic metal emission shows a clear declining trend as shown in Figure 5.12. This is caused by the decline of the metal-based industries in the 80’s. This sub-sector contributed 68% of the total load in 81-82 that fell to only 28% in 91-92.

Emission of toxic chemicals