MONOSODIUM glutamate, commonly called MSG, has long been a target of Green Power founder Simon Chau Sui-cheong's wrath. It recently got its own back, however, when he was hit by a classic reaction against the additive while lecturing at the Baptist College. Soon after he'd finished a restaurant meal, Dr Chau was overcome by a raging thirst, flushed face and confused thoughts, forcing him to dismiss the class early. It was a troubling experience for Dr Chau - Hongkong's best-known environmentalist - who helped run Hongkong's first anti-MSG campaign six years ago. Part-boy scout, part-zealot, Dr Chau has made numerous television and radio appearances, and written dozens of columns for newspapers and magazines. He is now taking his campaign to mainland China. He will act as an adviser and take part in China's first environmental awareness campaign, which starts this month, with more than 30 concerts planned over the next eight months in most of China's big cities. Dr Chau has also struck a deal with Chinese officials to send free copies of Green Power books and pamphlets, such as 100 Ways to Save the Planet, for mainland distribution. For a man as outspoken and committed as Dr Chau, it has not been an easy task to link up with green groups across the border, which are becoming more active. Dr Chau promotes a sometimes eccentric message, which encourages lifestyle changes such as eating ''living'' or uncooked food, and education outside the school system, which he says destroys self-esteem. Such outspoken views may have to be toned down so not to arouse suspicious Chinese reaction. ''We want to impress on [the Chinese] that we are harmless - politically at least. If we tell them we want to change society by turning green, they will become suspicious,'' he said. ''It's quite difficult to explain to them about changing society culturally, which is what Green Power is about, so we have to stick to the scientific basis, to things like water quality and energy use - not the ethical side.'' He has sought to boost his credibility with mainland officials by impressing his academic credentials, which include a master's degree in science and a doctorate. in applied linguistics. Dr Chau explained Green Power's hopes to extend its message to the mainland. ''If China is dirty, there is no hope for Hongkong. As China has one-quarter of mankind, if it is going to be dirty, the outlook for the planet is hopeless,'' he said. Surprisingly, he believes Hongkong, a city not well-known for its environmental awareness, could be a green model for China by 1997, particularly because of the boom in popularity on the mainland of everything Cantonese. ''It's not China that's overtaking Hongkong, it's Hongkong that is overtaking China. China wants to become Hongkong,'' he said. But making Hongkong an appropriate green model will remain an onerous task for groups such as Green Power. In a city where consumerism rules and shopping is a family pastime, Dr Chau has his work cut out preaching the need to use less energy and buy fewer things. At home Dr Chau sticks to a limited wardrobe of clothes made from natural fibres and goes without an iron, an air-conditioner or television set. In his campaigning, he keeps the focus on food and other issues which affect people's health. ''After all these years I realise that if you talk about pollution, you don't get a lot of support from the Chinese community. Ecology or the ozone layer or global warming are too remote for them,'' he said. ''Instead there are three things people find appealing: health, education, and China, which has a very big appeal to the hearts of people.'' BUSINESSES looking for an unusual outing for their staff are invited to take part in a Friends of the Earth tree-planting drive. Operated under the aegis of Agriculture and Fisheries Department's annual community tree plant, the green group aims to have 10,000 new trees in place between now and April 30. Planting will be carried out in Mui O on Lantau Island and in the Sai Kung Country Park, in areas destroyed by hill fires. Plots are within 40-to 50-minute hiking distance. A fee of $100-a-head gets two seedlings and tools for planting. Profits go to Friends of the Earth. For details, contact the group at 528-5588. If you have an environmental project of interest or wish to call to attention to an environmental problem in your neighbourhood, please fax the information to Ecowatch on 811-1278, or mail it care of the South China Morning Post.