A FOREIGN expert on aerial spraying didn't deny that "people near crops should be very careful" when there are fertilizer spraying operations.

Thus, Dr. Andrew Hewitt, bio aeronautics expert, is advocating for aerial spraying regulation rather than its prohibition.

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"I think when there are people near the crops, you should be very careful at spraying but when there are none, then you can spray a little bit more relaxed. But I also believe aircraft is the better application," Hewitt said during a press conference at Grand Regal Hotel in Davao City.

"(Because) when they use spray booms, you have to think of the length of the boom, the extent of the spray. With spray booms, the fertilizer goes up or sideways while fertilizer through aerial spray will go down if done properly," Hewitt said.

Hewitt said the best time to use aerial spray is during the morning when there is less wind activity.

"The work that we do covers work exposure and we do look up to prevent people (from exposure). We do research for years on the range of conditions that could occur and effect people, fish, native crops and neighboring crops. We did hundreds of studies on different aircrafts, different profit size, temperatures, wind speed, humidity, (and) height," Hewitt said.

"It's not just people we're trying to protect but also the environment and human health," he added.

Hewitt was invited by the Department of Agriculture-Fertilizer and Pesticides Authority (DA-FPA) to speak on the issue and is willing to provide assistance "if requested by FPA."

The FPA also hosted Hewitt's visit to Sitio Camocaan in Hagonoy, Davao del Sur.

"If there are concerns, (the people near the crop areas) may close their windows, take the clothes out of the clotheslines, and stay inside the house," Hewitt said.

He admitted that many studies have been done in other countries on aerial spraying.

FPA executive director Dr. Norlito Gicana said the agency have long created guidelines on the use of aerial spray but is willing to absorb recommendations from Hewitt on aerial spray regulation.

Guidelines include use of buffer zones that are not followed by a number of plantations.

Gicana said more studies should be made "to complement" previous studies made by agencies and groups from the country, which include the Department of Health (DOH).

"We feel that (there should be more) further study to make the (studies) more acceptable. (After all) we're also concerned not only on the efficacy of the product but also of health and the environment," Gicana said.

Hewitt conducted on Wednesday a forum on aerial spraying, together with scientists from the University of the Philippines. The "Technical Forum on the Science Behind Aerial Spraying" was conducted under the auspices of the 15th Anniversary Symposium Series of UP Mindanao in cooperation with FPA.

Hewitt is the manager of chemical applications research and training (Cart) at Lincoln Ventures Limites, a science and technology company of Lincoln University in Canterbury, England. He has done extensive voluntary work for technical committees of several international societies, organizations in Australia and the US who he himself published hundreds of peer-reviewed journal publications on aerial spraying and its drift mechanics.

Hewitt has contributed to hundreds of studies worth millions of dollars in countries that used aerial spraying to fertilize rice crops, banana plantations, and palm oil plantations, among others.