Faculty of Pharmacy, World University of Bangladesh
Dhanmondi, Dhaka, Bangladesh

ABSTRACT Environmental pollution and food contamination are as old as the civilization itself. It is the consequence of the development of civilization, over utilization of nature, industrialization and in fact a price for the progress. It is highly prominent in Dhaka city. Air pollution is mainly due to the vehicle emission, industrial discharge and burning of fossil fuel. The water resource of Dhaka becomes a major health threat due to arsenic contamination, inadequate household/industrial/medical waste disposal and industrial effluent management. Food contamination came from the commercialism of business people who are doing this knowingly to maximize profit. Necessary steps are to be taken to protect the environment for our own existence. This paper reveals chemical pollution and contamination issues of Dhaka city, the capital of Bangladesh.

Reference Id: PHARMATUTOR-ART-2637

PharmaTutor (Print-ISSN: 2394 - 6679; e-ISSN: 2347 - 7881)

Volume 7, Issue 01

Received On: 30/11/2018; Accepted On: 20/12/2018; Published On: 01/01/2019

How to cite this article: MOHIUDDIN, A. 2019. Chemical Contaminants and Pollutants in the Measurable Life of Dhaka City. PharmaTutor. 7, 1 (Jan. 2019), 25-37. DOI:

Abbreviations: BDL (Below Detection Limit); BOD (Biochemical Oxygen Demand, also called Biological Oxygen Demand); COD (Chemical Oxygen Demand); DO (Dissolved Oxygen); TDS (Total Dissolved Solid); PH (A logarithmic scale used to specify the acidity or basicity of an aqueous solution); ICDDR, B (International Centre for Diarrheal Disease Research, Bangladesh).

Purpose of the study: Brief review of chemical induced pollution and contamination, their consequences and control. Healthcare providers/Policy makers have a major role play to concerned field.

Materials and Methods: Comprehensive literature search followed by consulting healthcare professionals about environmental pollution and food contamination. Hospital, clinic and company personnel, newspaper journalists, NGO workers given their valuable suggestions and asked help for necessary books, journal, newsletters. A few western magazine and newspapers also observed to get necessary concern. Projections were based on public life pattern, their food habits, pollution and contamination sources, waste disposal features of urban life as well as industry and hospital waste disposals.

Results and Discussions: Pollution and adulteration are the most notorious enemy of mankind. Civilization has its own drawback that even causing destruction of itself. Very few people raised voice on this but crippled by the facts of commercialism. The scope of this article is limited to chemical pollution of air and water, medical or household waste products and food contaminants and adulterants. A few discussions based on real life experience and recent studies or reports from various journals and news articles are summarized here.

Findings: Both general people and the old system, are responsible for this unlivable condition of Dhaka city. Population is not the sole for this instance. A sense of poor rules and regulation is always raised everywhere. Negligence is becoming a contagious disease contaminating illiterate to well educated, all kind of people.

Research limitations: Many articles and documents found in concerned area of research, but the scope of this research is on its focus point chemical hazards and burdens of Dhaka city. Still the most important aspect is covered, but fact is less amount of recent data found in few areas.

Practical Implication: The language of this article is too simple to understand by people with simple literacy.  Journalists, doctors, students, nurses, pharmacists, public representatives, policy makers and regulatory authorities have to acquire much from this article.

Social Implication: Any article or research is based on the think beneficence for mankind, at least going ahead from the present situation, overwhelming problems and measures. The article should create a direction for the future policy makers of both government and other sectors to review the frustrating situation of chemical pollutions and food contaminants of Dhaka, along with the whole Bangladesh. Again, world business is moving to Asian countries, Bangladesh will be a major business hub within next few decades. This article should remind policy makers that we should not forget mankind, giving places to industrialization and development.

Contamination is the presence of an unwanted substance where it should not be or at concentrations above recommended. Pollution is contamination that results in detrimental biological effects to resident communities. All pollutants are contaminants, but not all contaminants are pollutants. All elements of the natural environment can be altered, sometimes with harmful results. Air, food, water, and the earth can all become sources of ailment, in the home, public, or work environments. In urbanization, all processes are viewed in relation to the city. Generally, better utility, good medical care, better food supply, education scope, jobs, industrialization, entertainment, electrification, specialization of professions are the basic causes of huge urban population growth. Better access to utilities and energy plays an important role in city development -- with this, people can relish all the modern facilities. Undeveloped areas got connected with road communication. It brings the people from those areas, for the use of media, technology, information for more standard living. With increased civilization and industrialization, both air and water, in Western or developing countries, contaminates with toxic substances that are either direct results of discharge or produced by photochemical degradation. Dhaka, being the capital of Bangladesh ranked 3rd worst in Air Quality Index (AQI) in the world. Besides, the city of nearly 20 million inhabitants, Dhaka faces challenges on this front, ranging from chemical outpouring, poor sanitation, river and canal water pollution from the surrounding industries, all resulting from the impromptu nature of urban civilization. Food contaminants and adulterants gave a new dimension in city life, together rest of the country. The healthcare providers role in environmental health is related principally to being alert to the conditions predominant in the community and of working with others to adequately control any of the attendant hazards.

Urbanization and Its Impact
Urbanization is one of 21st century’s most developing trends. Cities are the dominant force in continual economic growth, development, and prosperity in both advanced and developing countries. In developed countries, the growth of the urban population has stabilized, and urbanization is taking place rapidly. Currently, 55% of the world’s population (four billion people) reside in urban areas which will be nearly 70% by 2050 (United Nations, 2018). By 2030, over 60% people will live in the cities (Megacity Challenges, Siemens AG), two billion more people will have migrated to cities-- placing uncommon pressure on infrastructure and resources, particularly those related to water (According to UN and World Bank) (Benedito, 2018). From 2016 to 2030, a 35% population growth is expected in the top ten megacities. Furthermore, as more than three-quarters (around 80%) of the world’s mega-cities are coastal, there will be a substantial impact on water ecosystems from ridge to reef. Because of this, local and regional authorities lead actions targeting water-related obstacles, including energy and water, an increased demand for food, housing gaps and climate change (NewNation, 2018 and Daily Sun, 2018). Forecasts indicate cities in developing countries including Dhaka, Karachi and Lagos will surpass cities like Osaka, New York and Sao Paulo by 2030 (Joal, 2014).  It demands an extra 50% energy and water that pressurize the sources and threaten global water security. This has an apparent effect on both economic development and public health.  It has been predicted that the urban population in Bangladesh will rise to between 90 and 100 million by 2050, which will be around 50% of the total population (Shishir, 2018). The leather tanning industry has been identified as one of the main causes of pollution in the Capital city of Dhaka of 10 million people of both environment and water. About 60,000 tons of row hides and skins are processed every year using chloride and ammonium sulphate, followed by dehairing during de-liming, solvent vapors release a huge volume of crude effluent into the open causing air and water pollution (Jahan, 2014).

Chemical Pollution and Contamination Due to Urbanization
Smog results from the interaction of the ultraviolet rays in sunshine and the unburned hydrocarbons of automobile engines or factories and smokestacks. These products, when trapped by the thermal inversion engendered by local topography, cause damage to mucous membranes and lungs when inhaled (Timothy, 2006). Acute episodes of air pollution have been found to exacerbate illness and even cause death in people who already have respiratory and cardiovascular diseases. Supporting evidence exists demonstrating that second-hand tobacco smoke increases the risk of cardiovascular diseases or cancer as well (WHO, 2014). According to World Bank's Country Environmental Analysis (CEA) 2018 report, air pollution lead to deaths of 46,000 people in yearly in Bangladesh (Ahmad, 2018). Waterborne infectious disease is very common today, all the public supplies are literally contaminated with water drainage system reported many places. Many complaints about the taste, appearance, and physical qualities of locally supplied water have led to a brisk in bottled water (Kun, 2012). Water contamination with ground-source chemicals (e.g., pesticides, fertilizers) remains an ongoing possibility. Food remains a significant vehicle of disease organisms (Wasim, 2009). Foodborne disease, more commonly but often incorrectly called “food poisoning,” is grossly underreported. In most instances the illness produced by contaminated food is mild and of short duration, but more severe outbreaks (such as hepatitis A, most commonly seen in public restaurants) can. Epidemics of food-borne disease are dramatic and sudden, and most people become sick within 6 to 24 hours after consuming the contaminated foodstuffs. The epidemic pattern of food-borne disease presents differently from the gastrointestinal symptoms (e.g., nausea, vomiting, and diarrhea) induced by intestinal enteroviruses occur (Foodborne Illness and Outbreak Investigation Manual, 2008).

The Dhaka City at a Glance
Living in Dhaka city endowed with a traffic jam, street foods, unplanned buildings, narrow road space, noise pollution along with environmental pollution and issues of contamination (Sadiq, 2018). Some people make joke like “Traffic jams teach us things like patience and how to plan ahead of time” (Azmin, 2015). Many people sleep roadsides, railway platforms, mosques and market places. People rushes this city for job, business and other opportunities like uninterrupted utilities. Along with general people, the city is also heaven for muggers, robbers, thieves, pickpockets, frauds, drug dealers and organized criminals (Puja, 2017). People rarely can see the sunrise or sunset due to thousands of buildings. hawkers are illegally occupying the public walkways, pedestrians are now forced to walk on the roads which raises the risks of accidents and adds to the already unbearable traffic congestion in those areas. Economist Intelligence Unit (EIU) surveyed 140 cities around the world for its Global Live-ability Index 2018, scoring them on over 30 specified parameters under five categories: Infrastructure, education, culture and environment and healthcare facilities (The Global Livability Index, 2018). All these things make this a difficult to breath place and a second worst place in the world to live in. Some 18,000 deaths from environmental pollution took place in 2015 in Dhaka (Environment Desk, 2016).

Air Pollution
The most profound chemicals found harmful    to    human    health    and    at    high    enough    concentrations (Table 1) can even be fatal are Carbon monoxide (CO), Sulfur dioxide (SO2), Nitrogen oxides (NOx), Ozone (O3), Hydrocarbons (HC) and Suspended Particulate Matter (SPM) found in places surround Dhaka. Possible health hazards found to be headache, eye-nose-throat irritation, allergy, lung injury, trauma and even death with long term exposure (Chen, 2007; Daily Prothom Alo, 2014; Mohammed, 2018).

(Mohammed, 2018)

The AQI in Dhaka during the winter, where more than 4,500 brick kilns operate, typically wavers above 250 – a level expressed unhealthy for all groups – but often spikes much higher (Stanford News, 2018). Brick kilns, unfit vehicles run by fuels with higher level sulphur, as well as construction works, rundown roads have been identified as major sources of air pollution (Imtiaz, 2018 and Independent Online Desk, 2018). Day by day the amount of dust include air pollution in the city has been increasing. The air quality, particularly in Dhaka has assuredly been getting worse. Air pollution, according to Thomson Reuters Foundation, caused largely by burning fossil fuels, is cutting global life assumption by an average of 1.8 years per person, making it the world's top killer (DhakaTribune, 2018). AQI 201 to 300 is marked as "extremely unhealthy" or hazardous air. At present AQI level of Dhaka has 309, which is in extreme "unhealthy" position (Ahmad, 2018).

Water Pollution
Moving on to the issue of water quality and pollution, the National Sustainable Development Strategy (NSDS) of Bangladesh identifies the following reasons behind degradation of surface water quality:

1. Insufficient enforcement of environmental regulations
2. Confusion about institutional responsibility for the quality of urban water bodies
3. Encroachment of rivers and water bodies
4. Rural-to-city migration
5. Unregulated industrial expansion (Ferdous, 2018).

The Rivers Buriganga, Shtalakhka, Balu, Tongi Khal and dholeswari which runs past Dhaka City, is at present one of the most contaminated rivers in Bangladesh (Asif, 2017). The city is suffering from an acute lack of domestic water supply. Water is involved   in the spread of contagious   diseases   in essentially   two ways. The well-known   direct   ingestion   of infectious   agent   when   drinking   contaminated water.  The second is due to a lack of sufficient water for personal solitariness purposes (WHO, 2011). Approximately 80% of   all   sicknesses    and   diseases    can   be   attributed    to inadequate   water   supply   and   sanitation worldwide (UN Secretary General, 2003 and Malik, 2012). However, the rivers and canals continued to be intervened, and more wastewater from houses and industrial units poured into the rivers without any treatment, with several major sources of contaminats being outside the city area—in Gazipur, Tongi, Savar, Ashulia (UNDP, 2010). According to Dhaka Water Supply and Sewerage Authority (DWASA), it can currently supply 75% of water demand, out of which 85% is from groundwater sources (Deep Tube wells) (Manoj, 2017). The presence of toxic metal lead in Elephant road, Dhaka.University, Jatrabari, and Demra area and toxic Pentachlorophenol (PCP) and actual pathogenic bacterial load in the WASA supplied drinking water from different areas of Dhaka city were found to be ineligible for human utilization (Table 2).

Table -2:  Lead, Cadmium, Chromium and Arsenic content in first 14 water samples *

Lead, Cadmium, Chromium and Arsenic content

(Murshed, 2013) * 2 table contents accommodated in 1.

Some 80% of wastes are being discharged into the rivers in Bangladesh. No wonder our water supplies are in unsecured. Around 250 industries are liberating chemical contaminants into the Buriganga and Sitalakhya river. Every day 4,000 tons of solid and 22,000 tons of tannery waste assimilates with water in Buriganga river. Sewage is being discharged directly into the rivers, and the low-lying parts around urban areas (Daily Asian Age, 2018). By 2021 the garments export target has been set at $50 billion. But the success comes at a huge substantial cost. The dyeing and finishing plants are the major contaminants of water. Turag that flows by Tongi is almost dead with pollution. Its water looks ink black and gives out such a bizarre smell (Inam, 2017). Wetlands around Dhaka city are being demolished through land development and scrapping of toxic effluents and crude sewage. Industrial effluents have totally destroyed the ecology of rivers near these large urban areas (Shishir, 2018). In Dhaka, 20 canals have escaped. Liquid and solid wastes, and heavy metals like copper, iron, lead, and nickel are deploring the BOD, COD, DO, TDS, PH of water (Jahan, 2014).



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