Thousands of people are affected by mosquito-borne diseases, mainly dengue, in Bangladesh every year. Experts have called for effective measures to contain the spread of the disease which turns fatal in many cases, especially when the patient is a child, with Dhaka being the hotspot of Aedes mosquitoes.
Nowadays, mosquitoes are a major health threat to public health as these tiny creatures have become more potent and dangerous due to unplanned urbanisation and the abrupt use of insecticides which has backfired.
Over the last several decades, various initiatives to prevent the spread of mosquitoes have turned out unsuccessful. As a result, mosquitoes are not killed by sprays, coils or other insecticides. Experts predict that mosquitoes will cause more trouble in the future.
To reduce the health risks, Dhaka North and South city corporations are conducting various activities, including larviciding and fogger machine fumes, to prevent the breeding of mosquitoes. But the most common method, spraying medicine through fogger machines, is very ineffective and found harmful to health.
Dengue outbreaks occur regularly during summer and monsoon. This year, the number of dengue patients admitted to hospitals till Friday was 1,624 with 1,433 recoveries and 13 deaths.
According to the Directorate General of Health Services (DGHS), 178 dengue patients are now receiving treatment at hospitals across the country. Of them, 148 are in the capital.
On the other hand, 281 people died of dengue infection in 2022; 101 in 2021, and 179 people died in 2020 and 2019. Last year, a record 62,282 persons were infected with the disease.
According to experts, the danger of various diseases including asthma, breathing problems, cancer, and lung and kidney complications is increasing due to harmful reactions of the anti-mosquito chemicals used to kill flying mosquitoes through fogging.
It is already conceivable how polluted the air in Dhaka is. On top of that, there is no data on how much damage is being done to the human body by the mosquito extermination campaign, but the use of chemicals like Malathion, Permethrin, Tetramin, and Doltamexni in fogging can cause cancer and kidney diseases along with damage to the respiratory system.
Experts believe that emphasis should be placed on the biological control of Aedes mosquitoes. Along with increasing public awareness to kill Aedes mosquitoes, such as keeping the breeding grounds clean, carrying out cleanliness campaigns, and not spraying this medicine everywhere, which is a threat to public health, the correct dose of medicine should be sprinkled in the breeding areas of Aedes.
At the same time, mosquito control activities require a team of skilled workers who have minimal knowledge of Aedes mosquito breeding grounds. Because spraying anti-Aedes medicine in a breeding ground for the Culex mosquito will not work.
The dangers of fogger machine fume came to the fore in a report sent by our correspondent from Khulna.
In every ward of Khulna city, medicines are now being sprayed using fogger machines to kill mosquitoes, resulting in an area becoming smoky within a minute, disregarding human movement.
Health officials of Dhaka and Khulna city corporations admit that it is important to create public awareness about the fact that this smoke is not only harmful to children's health but also to everyone.
Runa Begum is a resident of Kalabagan Lake Circus Road, where the prevalence of mosquitoes is significant. “As the adjacent building is the councillor's residence, the city corporation workers spray with fogger machines 2-3 times every week.
“But the problem is that even if you get rid of mosquitoes by spraying, the smoke and the smell of the spray are very difficult to tolerate. It creates headaches, and burning in the throat, eyes and face. Children are the main victims of the fumes.”
Sharmin Akhter, a resident of Shukrabad area, shared a similar experience. She said even though the sprays might work, there is no advance warning for spraying. “Sometimes, they spray medicines when someone is eating and sleeping at home with windows kept open. The smoke is directly entering their bodies. Thus, health risks are increasing,” she said.
Mamun Mridha, a resident of Mohammadpur Shia Mosque area who works in a private hospital, noted that the sprayers have no protection other than wearing a mask.
Dhaka South City Corporation Health Officer Dr Fazle Shamsul Kabir claimed that the insecticide that they are spraying is completely safe for all kinds of animals, except for mosquitoes.
“We use this pesticide only after the test results are positive from two internationally recognized labs. The Ministry of Environment also wanted to know about the impact of the fumes. Even three-month-old babies are also safe,” he said.
“We are now working in two parts: spraying insecticide with fogger machines and spraying insecticide in the breeding grounds to kill Aedes mosquito larvae in the morning.”
On the other hand, Chief Health Officer of Dhaka North City Corporation Brigadier General Jobaidur Rahman said that spraying pesticides mixed with water through the fogger machines certainly has some harmful aspects.
“For example, it is harmful to someone who is an asthma patient, or a child. But we use this pesticide in a certain quantity or level so that it is not harmful to the environment and public health.”
In Khulna, the city corporation workers visit different areas regularly and fumigate by applying insecticides. Even if the adults are careful, the children run around in the smoke which is having a negative effect on their health.
Jabbar Molla of Gobarchaka said the children run out of the house when they hear the sound of the fogger machines and start playing in the smoke. But the city corporation people do not take it into account.
Abdul Aziz, the head of KCC's conservancy division, said that the chemical used in the fogger machines has very little effect. “We'll instruct the workers about it in the future,” he added.
Dr Swapan Halder, health officer of KCC, said the smoke of mosquito repellent is not only harmful to children's health but also to everyone. “It is also important to create public awareness about this,” he said.
What the experts say
Md Iqbal Hossain, director of the Khulna Divisional Department of Environment (DoE), said that the anti-mosquito drugs are harmful to humans let alone the children. “So we have to be careful while spraying medicine in fogger machines. Besides, the city corporation should also increase monitoring of the matter.”
Professor Mustafa Sarwar of the URP Department of Khulna Engineering and Technology University deplored the lack of guidelines for spraying medicine with a fogger machine in public places.
He said: “It is important to follow the rules of spraying the medicines effectively so that mosquitoes in the targeted spots are killed. Secondly, if you come in contact with this smoke 1-2 times, you may get a headache. But if you are constantly exposed to this fume, the possibility of physical harm is more likely to happen.”
Public health expert and Professor at the Health Economics Institute of Dhaka University Syed Abdul Hamid said that the pesticides sprayed by fogger machines to prevent mosquito breeding are harmful to health.
“In addition, coils, and various sprays that we use at home are also very harmful to humans, especially the elderly, children, and pregnant women,” he said, suggesting proper analysis of quality and effectiveness of the pesticides.