Free access article

Issue Environ. Biosafety Res. Volume 3, Number 4, October-December 2004 Page(s) 197 - 207 DOI 10.1051/ebr:2005003

Environ. Biosafety Res. 3 (2004) 197-207
DOI: 10.1051/ebr:2005003

An algorithm for estimating potential deposition of corn pollen for environmental assessment

Shigeto Kawashima¹, Kazuhito Matsuo¹, Mingyuan Du¹, Yuichi Takahashi², Satoshi Inoue¹ and Seiichiro Yonemura<sup>1

1</sup>  National Institute for Agro-Environmental Sciences 3-1-3 Kannondai, Tsukuba 305-8604, Japan
²  Yamagata Prefectural Institute of Public Health 1-6-6 Tohkamachi, Yamagata 990-0031, Japan

(Received September 17, 2004; accepted February 13, 2005)

Abstract
The safety and impact on the environment of transgenic crops are important issues, and studies have shown that pollen from transgenic Bt (Bacillus thuringiensis) corn (Zea mays L.) may kill nontarget insects. To develop an algorithm for assessing the environmental effect of transgenic crops, we arranged a field experiment in Tsukuba, Japan. Pollen dispersal and deposition were measured inside and outside a cornfield throughout the flowering period. Weather conditions such as wind speed and direction were measured at the same time. Pollen dispersal peaked 1 week after the start of flowering and continued for 12 days thereafter. The variation in daily pollen dispersal was similar at all observation points. Both pollen dispersal and deposition decreased exponentially with distance from the cornfield on all days. We estimated potential pollen deposition with a quasi-mechanistic model that incorporates the effects of wind direction, wind speed, and flowering intensity. The daily potential deposition was summed over the flowering period, and then the relationship between distance from the cornfield and the integrated potential deposition was estimated. It was possible to show the effective area of the environmental risk zone posed by genetically modified pollen by combining the distance/deposition relationship with the dose/response relationship derived from a laboratory assay. The algorithm described here can be applied to various wind-pollinated plants to estimate both potential and integrated pollen deposition.

Key words: transgenic crops / pollen deposition / meteorological effect / estimation model / risk assessment

Corresponding author: Shigeto Kawashima sig@affrc.go.jp

© ISBR, EDP Sciences 2004

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