In recent times, a concerning trend has emerged in Bangladesh’s construction industry, with local cement manufacturers increasingly turning to fly-ash mixed cement instead of traditional Portland grey cement. While this shift may seem innocuous at first glance, it poses a significant threat to the country’s existing and future infrastructure. Fly-ash, a byproduct of coal combustion, not only compromises the structural integrity of buildings but also poses grave risks to public health.
Bangladesh, like many other nations, faces the challenge of managing fly-ash produced by coal-fired power plants. Traditionally, fly-ash was disposed of in ways that harmed the environment, prompting regulations to control its handling. However, with the rise of fly-ash mixed cement, there’s a disturbing new avenue for its disposal, one that directly impacts the nation’s infrastructure and its citizens’ well-being.
The economics behind this shift are troubling. Cement production typically relies on a combination of clinker and gypsum, with clinker constituting 95 percent of the mix. However, faced with escalating clinker prices, some unscrupulous traders have turned to substituting fly-ash for clinker, seeking higher profits while maintaining competitive prices. What’s alarming is that in Bangladesh, fly-ash mixed cement is being sold at prices comparable to traditional Portland grey cement, indicating potential foul play in the industry.
Fly-ash itself is a hazardous material, containing a cocktail of heavy metals such as mercury, arsenic, manganese, copper, cadmium, nickel, and lead. These toxic elements, present in coal in varying concentrations, pose significant health and environmental risks. During coal combustion, volatile elements like arsenic and mercury can redeposit on fly-ash particles, exacerbating its toxicity.
Studies reveal that fly-ash typically contains heavy metal concentrations several times higher than those found in coal. When leached into the environment, these toxic elements can disrupt ecosystems, contaminate soil and groundwater, and enter the food chain, ultimately threatening human health. The leaching of heavy metals from fly-ash can exceed permissible levels, jeopardizing water quality and public health standards.
The international community has recognized the dangers of fly-ash, with some jurisdictions taking decisive action to mitigate its risks. In the United States, for instance, a state banned the use of mercury-tainted coal fly-ash at a cement plant due to concerns about airborne mercury pollution. Similarly, India imposed a ban on mixing fly-ash in cement, acknowledging the hazards it posed to both the environment and public health.
Despite these precedents, Bangladesh appears to be moving in the opposite direction, with cement manufacturers ramping up the use of fly-ash mixed cement. This trend not only compromises the integrity of infrastructure projects but also raises serious questions about public safety and regulatory oversight.
Moreover, the economic incentives driving this shift are troubling. Cement manufacturers are reportedly receiving fly-ash from sources such as India at little to no cost, raising suspicions of financial impropriety. By substituting fly-ash for clinker, these manufacturers may be reaping substantial profits while endangering the country’s infrastructure and population.
The widespread adoption of fly-ash mixed cement in Bangladesh poses a grave threat to the nation’s infrastructure and public health. The unchecked use of this hazardous material not only compromises the integrity of construction projects but also exposes citizens to toxic heavy metals with long-lasting environmental and health consequences. Urgent action is needed to address this growing crisis and safeguard Bangladesh’s future development.
Here are a few examples of countries where the use of fly-ash mixed cement is either banned or restricted:
United States
In some states, there are restrictions on the use of fly-ash mixed cement, particularly if it contains high levels of hazardous materials such as mercury. Regulations vary by state, and some have imposed bans or limitations on its use in certain applications.
India
While the use of fly-ash in cement production was previously banned in India, regulations have evolved over time. Currently, there are restrictions on the percentage of fly-ash that can be used in cement, and standards have been put in place to ensure its safe incorporation.
European Union
The EU has regulations governing the use of fly-ash in construction materials, including cement. These regulations aim to minimize environmental and health risks associated with the use of fly-ash, particularly concerning heavy metal contamination.
Australia
In Australia, regulations govern the use of fly-ash in construction materials, including cement. While there are no outright bans, there are standards and guidelines in place to ensure its safe use and minimize environmental impacts.
Canada
Similar to Australia, Canada has regulations and guidelines governing the use of fly-ash in construction materials. While there are no nationwide bans, individual provinces may have restrictions or guidelines in place.
According to experts, the decision to replace Portland Grey Cement with fly-ash mixed cement is not inherently good or bad. It depends on various factors including the specific context, regulations, environmental considerations, and the quality of the materials being used. In Bangladesh unfortunately, no one is paying attention to this crucial issue while the media remains totally silent as they are dependent on advertisement revenue that they accrue from the cement manufacturers.
