Monday, February 11, 2019 - 838 hours ago
Presence of heavy metal particles in Dhaka's air has exceeded the level even many polluted cities have experienced, seriously affecting public health, especially the children, in recent times. Metals such as lead, cadmium, zinc, chromium, nickel, arsenic, manganese, and copper that can cause fatal diseases like cancer were found in alarming proportion in the Dhaka city's air, according to two studies carried out in December 2018 and January 2019. Dust in Dhaka city contained 200 times higher than generally acceptable level of cadmium, supposed to be present in the soil, revealed the study reports published in Science of the Total Environment and Environmental Science and Population Research this month. Lead and nickel were found to have been more than double in Dhaka's air. The researchers further detected arsenic in an alarming proportion in the city air. These particulate matters, researchers say, are so fine that they can easily come in contact with skin and enter human body through foods and drinks (Prothom Alo, January 21, 2019).
Environmental Performance Index (EPI) is one of the most widely used measures of well-being. The weak point of this index is that it does not take into account the concept of sustainability and, more precisely, it is lacking in the environmental component specification. On the other side of the spectrum, some indicators provide useful information about the environmental health of countries but not about human development, such as the Environmental Performance Index (EPI).
One of the biggest problems that we are facing today is that of environmental pollution. Environmental pollution is an undesirable change in the physical, chemical or biological characteristics of air, water and soil that may harmfully affect the life or create potential health hazard of any living organism. It’s increasing with every passing year and causing grave and irreparable damage to the earth. Environmental pollution consists of five basic types of pollution, namely, air, water, soil, noise and light. Pollution is thus direct or indirect change in any component of the biosphere that is harmful to the living components.
Pollution refers to the very bad condition of environment in terms of quantity and quality. Pollution control is a term used in environmental management. It means the control of emissions and effluents into air, water or soil. Without pollution control, the waste products from over consumption, heating, agriculture, mining, manufacturing, transportation and other human activities, whether they accumulate or disperse, will degrade the environment. In the hierarchy of controls, pollution prevention and waste minimization are more desirable than pollution control.
The sources and causes of environmental pollution include the following: (1) Industrial activities: The industries all over the world that brought prosperity and affluence, made inroads in the biosphere and disturbed the ecological balances. The improper disposals of industrial wastes are the sources of soil and water pollution. Chemical waste resulting from industry can pollute lakes, rivers and seas and soil too as well as releasing fumes; (2) Fuel emissions: The smoke emitted by vehicles using petrol and diesel and the cooking coal also pollutes the environment. The multiplication of vehicles, emitting black smoke that, being free and unfettered, spreads out and mixes with the air we breathe; (3) Rapid urbanization and industrialization: The urbanization and the rapid growth of industrialization are causing through environmental pollution the greatest harm to the plant life, which in turn causing harm to the animal kingdom and the human lives; (4) Population overgrowth: Due to the increase in population, particularly in developing countries, there has been surge in demand for basic food, occupation and shelter; (5) Environmental pollution has negatively affected both human beings and animals. Almost all of our success in the fields of industrial progress, science and technology had so far been realised at the cost of our health. Even our flora and fauna were found to be threatened with extinction.
Pollution is the effect of undesirable changes in our environment that have harmful effects on all living organisms. During the last few decades we have polluted our environment on which life itself depends with a variety of waste products.
Human impact on environment in several ways, some common effects include water quality, environmental pollution and greenhouse gas emissions, depletion of natural resources and contribution to climate change. Some of these are the direct result of human activities, whereas others are secondary effects that are part of a series of actions and reactions. Though, technology is making lives of humans easier and comfortable. It poses a great threat to the environment. The threat is due to pollution, radiation hazards, exploitation of natural resources etc. Greenhouse gases and aerosols affect climate by altering incoming solar radiation and out-going infrared (thermal) radiation that are part of earth’s energy balance. Changing the atmospheric abundance or properties of these gases and particles can lead to a warming or cooling of the climate system.
Recently published report “Air pollution in Asia and the Pacific: Science-based solutions” identifies 25 clean air measures that can positively impact human health, crop yields, climate change and socio-economic development. The climate isn’t the only challenge we face. Interpersonally, the report notes, we are also struggling. For many people, “this is an increasingly anxious, unhappy and lonely world. Anger is increasing and empathy appears to be in decline.” Technology addiction is cited as one cause. Moreover, we don’t know what’s coming next, and our lack of control manifests itself as psychological stress. Globally, mental illness is rising, with approximately 700 million people now suffering from a mental disorder. Five of the top 20 diseases “in the global burden” are mental ones. The air pollution in Asia and the Pacific: Science-based solution is the first-ever comprehensive scientific assessment of air pollution outlook in the region. It outlines 25 clean air measures that could achieve safe air quality levels for 1 billion people by 2030 – with numerous benefits for public health, economic development and the climate. This handbook provides an overview of the 25 clean air measures for Asia Pacific.
(1) Strengthen emission standards for road vehicles: Strengthen all vehicle emissions standards with a special focus on regulation of light and heavy-duty diesel vehicles. This will require collaboration between environmental agencies, transport agencies, oil companies and vehicle manufacturers, among others.
(2) Regularly maintain and inspect vehicles: Introduce legislation and enforcement of regular mandatory emission checks and maintenance. This includes random tests to prevent extended use of vehicles with failed emissions abatement systems. Centralize inspection and maintenance systems and establish self-funding mechanisms for regular audits at test centres.
(3) Mainstream electric vehicles: Develop fiscal and non-fiscal policies to promote electric mobility. Invest in required infrastructure to encourage quicker uptake of electric vehicles.
(4) Provide better mobility options: Improve public transport system to encourage shift from private passenger vehicles to public transport and integrate with sustainable urban planning. Invest in walking and cycling infrastructure (sidewalk and bike-paths, sufficient lighting, bike sharing option, etc).
(5) Control dust from construction and roads: Suppress construction and road dust through dust control measures including road washing and cleaning, road paving, water spraying, installation of barrier protection, avoiding dust-generating work during windy days, etc. Increase green spaces and areas especially in cities. This includes public parks, gardens, etc.
(6) Reduce emissions from international shipping: Require low-sulphur fuels and control of particulate emissions. Collaborate with the International Maritime Organisation to widen the ratification and implementation of International Convention for the Prevention of Pollution from Ships.
(7) Improve post-combustion control: Introduce state-of-the-art end-of-pipe measures to reduce sulphur dioxide, nitrogen oxides and particulate emissions at power stations and in large-scale industry. Examples include flue gas desulphurization for sulphur dioxide, selective catalytic reduction for nitrogen oxides, and high efficiency particulate matter controls like fabric filters, multistage electrostatic precipitators.
(8) Strengthen industrial process emissions standards: Introduce advanced emissions standards in industries, e.g., iron and steel, cement, glass production, chemicals, etc. Strengthen production, performance and emission standards to control end-of-pipe emissions and fugitive emissions. This will stimulate investment in pollution control and/or cleaner technologies.
(9) Introduce efficient brick kilns technology: Improve efficiency and introduce emissions standards to stimulate shift to more efficient brick kiln technologies (such as zigzag, vertical shaft brick kiln or tunnel kilns). This requires collaboration among kiln owners, technical experts, and government to demonstrate benefits of cleaner kiln technology.
(10) Control methane from oil and gas production: Encourage recovery of oil production and associated petroleum gas. Stop routine flaring and either utilize or convert to liquids that can be sold at higher value. Improve leakage controls in gas production and distribution networks.
(11) Improve solvent use and refinery controls: Introduce low-solvent paints for industrial and do-it-yourself applications. Improve solvents recovery in industry. If not feasible, incinerate flue gas rich in hydrocarbons. Establish leak detection and repair programmes at refineries. Install double seal systems, vapor recovery unit, fixed covers and monitoring at refineries and fuel depots.
(12) Use environmentally-friendly refrigerants: Ensure full compliance with Kigali Amendment to phase-down hydro fluorocarbons which are commonly used in air conditioning, refrigeration and a host of industrial products. Establish regulations to support shift to low- global warming potential cooling agents.
(13) Provide clean cooking and heating options: Use clean fuels – electricity, natural gas, liquefied petroleum gas in cities, and liquefied petroleum gas and advanced biomass cooking and heating stoves in rural areas. Substitute coal with briquettes for cooking and heating.
(14) Strictly enforce bans on household waste burning: Strictly enforce bans on open burning of household waste. Burning ban needs to be complemented with comprehensive solid waste management plan including proper waste collection system, recycling, waste treatment, and awareness raising.
(15) Provide incentives for improved energy efficiency in households: Provide incentives to improve energy efficiency of household appliances, buildings, lighting, heating and cooling. Encourage rooftop solar installations.
(16) Increase renewable electricity generation: Establish renewable energy targets and supporting policies to achieve target. This includes providing incentives to foster extended use of wind, solar and hydro power for electricity generation and phase out least efficient plants. Leverage public pressure to switch from fossil fuels to renewable.
(17) Improve energy efficiency for industry: Introduce ambitious energy efficiency standards for industry. Include energy efficiency targets for industry in national development plans.
(18) Recover coal mining gas: Encourage pre-mining recovery of coal mine
methane gas. Provide fiscal incentives, well-defined gas property rights and unsubsidized free gas market.
(19) Improve livestock manure management: Introduce covered storage (floating or permanent covers) and efficient application of manure (when plants need fertilizers, rapidly incorporate manure in soil or as narrow bands in canopy or grassland). Consider low emission options for new animal housing: Regular floor scraping, air ventilation cleaning, closed storage tanks.
(20) Strengthen management of nitrogen fertilizer application: Establish efficient nitrogen fertilizer application (right timing and amount). Substitute urea and ammonium bicarbonate with e.g. ammonium nitrate fertilizer. Promote alternative formulations, e.g., neem coated urea, or use of urease inhibitors, where available and affordable.
(21) Better management of agricultural crop residues: Manage agricultural crop residues, including strict enforcement of bans on open burning. Complement burning ban with measures that use the residues. This includes alternative off-site use, technologies that plough residue into fields, no-till agricultural practice, or using residues as bedding for livestock or biogas digesters.
(22) Prevent forest and peat land fires: Improve and enforce forest, land and water management and fire prevention strategies. This includes fire spread protection zones, fire alarm and brigade system, prohibits access to forests during droughts, and ban on land clearing.
(23) Promote more efficient rice production practices: Encourage intermittent aeration of continuously flooded rice paddies (e.g. alternative wetting and drying – practice of allowing the water table to drop below the soil surface at one or multiple points during a growing season).
(24) Stop biogas leakage from wastewater treatment: Introduce well-managed two-stage treatment with biogas recovery. Promote decentralized wastewater treatment units.
(25) Improve solid waste management: Encourage centralized waste collection with source separation and treatment, including gas utilization.
Finally, the control of the emission of various contaminants into the environment which brings down the level of the pollution is done by various updated methods. The various technologies which control the pollution are bioremediation laser methods, chemical methods, nanotechnology etc. Phytoremediation is a way to mitigate environment pollutions, such as in air, water and soil pollution in virtue of plants, more often than not, combined with their associated microorganisms. This concept has been widely applied to treat pollutants in soil and water. Vapour recovery is the process of recovering the vapours of gasoline or other fuels, so that they do not escape into the atmosphere.
The writer is former Head, Department of Medical Sociology,Institute of Epidemiology, Disease Control & Research (IEDCR),Dhaka, Bangladesh, E-mail: firstname.lastname@example.org