On banning of aerial spraying of pesticides

Tricking the President?
HIDDEN AGENDA By Mary Ann Ll. Reyes (The Philippine Star) Updated February 10, 2010 12:00 AM

Former Health Secretary Francisco Duque may not have been totally forthright with the President when he asked her to issue an executive order that will ban aerial spraying of pesticides for agricultural purposes.

In his memorandum to Mrs. Arroyo, Duque said the World Health Organization (WHO), in a letter to the Department of Health (DOH), has recommended banning aerial spraying based on their experts’ peer review of a DOH-commissioned study.

What Duque failed to tell the President is that the WHO, in the same letter to the DOH, clearly stated that it does not have a formal position on aerial pesticide spraying here.

In early September last year, the DOH requested the WHO to organize a panel of experts who could “peer review” the DOH-commissioned health and environmental assessment study of Sitio Camocaan, Hagonoy, Davao del Sur, residents of which non-government organizations claim have been the victim of aerial spraying.

The experts’ findings were discussed in a teleconference held on Oct. 19, 2009 at the WHO regional office in Manila. Among those who attended are WHO representatives led by Dr. Soe Nyunt-U, two of the three experts – Dr. David Coggon of the United Kingdom and Dr. Brian Priestly of Australia – who peer reviewed the study, and representatives from the DOH, Fertilizer and Pesticides Authority/Department of Agriculture, Department of Environment and Natural Resources, Department of Labor and Employment, University of the Philippines (UP)-National Poison Management and Control Center and Philippine Society of Clinical and Occupational Toxicology.

WHO experts found several major limitations in the study, authored by Dr. Allan Dionisio, so they could not recommend a banning of aerial spray based on it. Instead, they suggested that the DOH to do its homework by reviewing available literature and data from other countries. In short, Dionisio’s study was not able to stand the scientific scrutiny of a peer review.

The international experts from the WHO found the study to be weak in the following points: small sample size leading to statistical uncertainties; other possible sources of exposure other than aerial spraying in banana, such spraying of other crops like mango; potential biases due to incomplete responses on health outcomes and measurement errors; inclusion of farm workers as subjects; lack of critical information on the assessment of exposures; history on the nature of pesticide application in the nearby banana plantation; over-reporting of symptoms and unvalidated interview information; domestic use and storage of pesticides; and, lumping all respondents (children and adults) without breaking down subjects by age and gender.

The third WHO expert, Dr. Aqiel Dalvie of South Africa, who was unable to participate in the teleconference, supports banning of aerial spray but recommended surveillance, environmental monitoring and further epidemiological study on health effects of pesticide usage.

The WHO experts recommended that national legislation should govern the use of pesticides and as well as the introduction of buffer zones where pesticides are applied to protect neighboring communities.

Dionisio, author of the DOH-commissioned study, explained during the teleconference that his study is a health and environment assessment and it is not focused on aerial spraying. According to him, “it is a technical report for the DOH officials and not intended to be published in a journal, thus the format was different.”

So much for his study, which only Duque seems to be taking seriously. If the WHO refuses to give its seal of approval to it, why should Duque allow it to be the basis of a national policy to ban aerial spraying?

The DOH-commissioned study did not have the scientific vigor to address whatever perceived health concerns that were earlier expressed by Dr. Romeo Quijano in his much-ballyhoed articles that convinced several sectors of civil society to advocate the ban. Quijano’s articles led the DOH to fund the study.

Other countries allow the use of aerial spraying, but regulate it to protect human health and the environment. In the Philippines, a 30-meter buffer zone is in effect but banana plantations here apply 50 meters. The buffer zone in Tasmania, Australia is 50 meters, in New South Wales 25 to 30 meters, and in the US, 15 for chlorothalonil (one of the substances used in banana plantations).

The size of the buffer zones depends on the product being sprayed. NGOs that have supported the ban on aerial spraying in banana plantations claim that the fungicide drift reaches as far as 3.2 kilometers. An international drift expert, however, clarified that the 3.2-km drift is for the eradication of locusts, mosquitoes and other insects since the airplane is flying higher over a community to cover a wider area, but not aerial pesticide spraying for banana plantations.

Dr. Andrew Hewitt of the University of Queensland and one of the few world experts on bio-aeronautics, said the airplane used in banana plantations here flies just over a few feet above the canopy of the bananas and sprays the fungicide down. Therefore, a 3.2-km drift as claimed by these NGOs is not possible.

Based on what he saw here, he concluded that aerial spraying in Davao can be among the best practices in the world because it’s done professionally and properly. He also supports the regulation, but not the banning, of aerial spraying of pesticides.

The proposed ban on aerial spraying has far-reaching consequences on the economy. Manual spraying is not only inefficient, it also exposes workers to the fungicide spray solution unnecessarily on a daily basis. The ban could kill the local banana industry and displace thousands of workers and their dependents.

Immediate banning of aerial spraying will displace a lot of people, and the economy will be affected because there will be thousands of hectares that cannot be sprayed as these do not have roads for ground spraying trucks.

The ProPinoy Project