We do not need centralized management systems, we need companies to limit pollution by dye-containing wastewater
They are widely used in the textile, food and pharmaceutical industries. But they pose a serious threat to plant, animal and human health, as well as to ecosystems around the world. They are synthetic dyes, which contaminate billions of tons of wastewater every year. Dye-containing wastewater pollution must therefore be tackled as soon as possible, according to an international group of researchers.
On the one hand, they suggest revising the rules on the basis of textile and industrial production, and on the other hand, developing sustainable technologies. These include a new membrane-based nanoscale filtration. However, it would be better to oblige industrial producers to eliminate dyes before they reach public sewerage systems or watercourses.
The work that analyzes the impact of pollution from dye-containing wastewater was published last week in Nature Reviews Earth & Environment. Research shows that currently up to 80% of industrial wastewater containing dyes in low- and middle-income countries is released untreated into streams or used directly for irrigation. This poses a number of direct and indirect threats to human, animal and plant health.
But nobody is doing anything to stop the problem. Given the complexity of treating dye-containing wastewater, a solution would be to switch from centralized or regional methods to a decentralized system. We need a site-specific source treatment, with obligations for industries to remove dyes from the wastewater they produce before they reach public water systems.
The textile industry is the biggest consumer of dyes like mauveina. Since 1865, when it was discovered, more than 10 thousand different types of dyes have been synthesized, with an estimated global annual production today of 1 million tons. They are used in the rubber, leather tanning, paper, food, pharmaceutical and cosmetic industries. However, 80% take the path of the textile industry, which generates about 70 billion tons of wastewater contaminated by dyes every year.
The impact of dyes on the environment and health
Untreated dyes cause staining of water bodies, reducing the degree of visible light passing through the surface layer. Thus, they hinder the photosynthesis of aquatic plants and create impacts along the food chain. The suppression of the transfer of energy and nutrients along the food chain can cause the collapse of entire aquatic ecosystems.
Fish also suffer from this pollution by dye-containing wastewater. The substances are deposited in the gills and penetrate the brain, causing toxicological effects such as uncoordinated movements, respiratory difficulties, liver damage and kidney dysfunction. These effects not only reduce the nutritional value of fish for predators but also lower their reproduction rates.
Negative impacts of dyes are also found on earth, where they disturb the balance of microbial communities in soil, and in humans. Exposure to dyes can trigger allergies, asthma, dermatitis and disorders of the central nervous system. They even increase the risk of cancer.
Faced with all this, politics can no longer stand by, according to scientists. We need to become aware of the problem and tackle it as soon as possible.