Status of herbicide use, regulatory management and case study of paraquat in Taiwan

Abstract

Herbicides are widely used to provide more effective and economic means of weed control in the crop production, horticultural use and landscape management. From the perspective of environmental ecology, food security and human health, it is necessary to control the release of the agrochemicals into the environment from a variety of applications. The purpose of this review was to examine the use and consumption of herbicides in the past decade and their regulatory management measures in Taiwan, and to describe the health hazards of herbicides commonly used in Taiwan. In addition, a case study on the regulatory measures imposed on paraquat use was described to highlight the impacts such measures can have on the environmental quality and potential for intentional poisoning. It showed that the sales quantities of main herbicides in Taiwan significantly increased from 14,287 MT in 2007 to 20,680 MT in 2016. Noticeably, the non-selective herbicides (including glyphosate, paraquat and glufosinate-ammonium) accounted for about 50% of sales quantities of herbicides in Taiwan’s market. Regarding the health hazards of herbicides, paraquat may be one of the most acutely toxic chemicals among them. The core regulations for protecting human health, food security and water quality resulting from the use of herbicides are captured by the Pesticide Management Act, which involves the registration, manufacturing, import, export, sales and use of all pesticides marketed in Taiwan. The regulation of paraquat use over time was described in a case study. In order to reduce the impacts of paraquat use on the environmental ecology and self-poisoning, the central competent authority in May 2017 announced its intention to ban the sales and use of paraquat, which will become effective in February 2019.