Environmental issues connected with pest control activity

Feb 01, 2012 22:30
It was around the middle of April when the first batch of expert pest control teams entered the devastated area (Kesennuma-city and Rikuzentakata-city). As the temperature was still so low that the highest temperature was below 10 degrees C in the Tohoku area back then, there were almost no emergences of adult flies.

However, we saw thousands of tons of fish waste piled up in many of the huge cold storage warehouses and marine product processing factories on the coast. Some devastated areas had fish waste scattered across several hundred thousand square meters. Under the scattered rotten fish, there were countless fly larvae, or worms, moving around such as we had never seen before.

Also, because there were puddles everywhere, the mosquito population exploded. It was easy to imagine the horrible plague of flies and mosquitoes. That would accompany the rising mercury as summer approached. However, it was difficult for local municipal governments to take prompt action under the circumstances, faced with so many staggering tasks in the wake of the earthquakes and tsunami.

Left: A Picture of the inside of an affected cold storage warehouse at the beginning of May 2011. A large amount of saury, salmon and bonito were rotting.
Center: A lot of fish waste flowed out from the cold storage warehouses and was scattered all around the cities. 
Right: Significant amounts of worms appeared in the fish waste from around the end of May. They were crawling on the surface, which later caused big problems with flying imagoes at each site.

NICCO is undertaking environmentally-friendly pest control work as follows:

 Selecting insecticide based pest control products
When you consider environmentally-friendly ways to conduct pest control, using insecticides involves taking risks. There is debate for and against our pest control activities here taking risks to environmental pollution and public health into account. We received opinions such as "Couldn't you kill the insects using natural products?" "You should clean up the fish waste" and "Drying the fish waste in the sun will kill the worms".

However, the reality was that these places faced such dire situations that it was just impossible both temporally and tangibly for the people there to implement the above mentioned ways to exterminate the insects. We thought that taking only environmentally-friendly pest control steps would result in towns full of insects, which would make living conditions very uncomfortable. For these reasons, we selected a pinpointed insecticide based pest control strategy with the idea that the following three characteristics were necessary: immediate effectively, residual efficacy and high insecticidal effect. 

As for pest control, however, we are making efforts to kill the insects while considering the environmental impacts as much as possible based on a benefit-risk analysis model. At the same time, we are also encouraging each municipality to collect the fish waste as well. 

 Flow of pest control  
Spraying only the needed amount of insecticide on only the needed points is our environmentally-friendly method of pest control. Here is how we do it. First, experts evaluate the infestation to find its source, and they spray as a pinpoint-treatment based on dosage and usage guidelines set by the Pharmaceutical Affairs Act. As it is not spraying in the air but spraying directly on the rubble and fish waste, we are also spraying with the highest possible consideration for the issue of drifting.

Larval worms that are in the growth stage just before becoming flying imagoes are the main focus. We will continue our research and make additional action in the future on an as needed basis, rather than regular, scheduled treatment.


 Insecticides in use
We choose insecticides which are the safest for humans and animals, fish and birds based on specialists' opinions. Etophenrox EC is the main insecticide we use. Fenitrothion, dichlorvos EC, which is an inexpensive alternative, is partly used at sites with no human activity where pest control is conducted. Also, given that sea gulls are coming to eat many worms and flies, Etophenprox EC is a good choice since it has little affect on birds. For mosquito larvae, we use AN IGR called "Pyriproxyfen WP" which inhibits their growth. This is a very safe substance as humans or animals and birds are not effected.

For example, the acute oral toxicity of etophenprox, which is the lethal component of Etophenprox EC is: LD50=11,900mg/kg. This is safer than that of salt, 3,500mg/kg. The insecticides we use leave little residue, so they will not have long term negative effects on the land. Before pest control activity, we make sure that people in charge of the municipality are told and we gain their approval.

 Pest control workers  
We have come to the conclusion that pest control by professionals in the field would be best after considering the safe use of pesticides and spraying equipment and effective ways of working. This led us to forming a business alliance with the Japan Pest Control Association, the only professional pest control entity in Japan, and people from not only Iwate and Miyagi prefectures have been working in this project, but people from all over Japan.  Japan Pest Control Association: http://www.pestcontrol.or.jp/

 Wearing protective clothing 
Spraying is done by people with Tyvek protective clothing that covers their entire body, and wear gas masks, goggles and gloves. The reason why people wear these things is not only to protect themselves from pesticides but also because of the huge amounts of mud and dust in the rubble and stench. They work with the best clothes for such situations.