HONG KONG: Turn the air-conditioning down, drain your dehumidifier to water the plants and tell your maid to buy Ecoballs for the laundry. Do not give a clock as a gift, do take insistent advice with good humor, try to avoid the number four, and don't think pushy people are rude - they're just ambitious.

Welcome to Hong Kong, where fast-moving sophistication meets old-fashioned superstition to produce a haze of thorny issues for the thousands of newcomers who move here every year to navigate.

Surprisingly, the market is not flooded with cross-cultural guidebooks. That mismatch of demand and supply goes a long way to explaining why two recently published guidebooks are selling out their first printings.

"Going Green in Hong Kong," by Catherine Touzard and Fabienne Malaval Dupré, is soon to appear in a new edition before it is even a year old. "Hong Kong Life & Culture," by Emily L. Y. Chan, is winning plaudits from expatriate groups for its ability to confront the chasm between West and East head on.

Green issues are moving to the top of the agenda around the world. Hong Kong - high-rise, densely packed, and on the edge of China - presents special issues and a certain urgency: Air pollution is dimming the once-spectacular views of harbor and mountain and causing concern among new arrivals for their health. The area also has long, hot and humid summers - so damp that the cooling effect of air-conditioners is not enough to prevent mildew from seeping into books and clothes.

Touzard, a French mother of four who has lived in Asia since 1989, and Dupré, a textile entrepreneur, tackle the immediate concerns (use low-energy fans instead of electricity-guzzling air-conditioners) and the broader issues.

The biggest problem for eco-warriors is that so much of her sound advice seems counterintuitive for a Hong Kong lifestyle. The city thrives on rampant consumerism; a favorite recreation is to go shopping in air-conditioned malls. Apartments are so small and neighbors so close that insulation means creating an air-conditioned cocoon of otherness.

"You can't complain about filthy air here and then run your air-con all the time," Touzard said - even though that is exactly what most Hong Kongers do.

Then there are the airplanes. "We have a huge carbon footprint, from very high imports, for example, of most of our food, and we fly a lot," Touzard said.

Rather than buying those air-freighted Tasmanian green beans, Touzard recommends local organic food. Do not, she warns firmly, even think of buying vegetables from mainland China, organic or not, as the soil there is showing the effects of decades of industrialization.

And since the weekly shopping in Hong Kong is often done by a domestic helper, Touzard offers a chapter on how to eco-train the maid. She should take her own shopping bag, buy Ecoballs - plastic dispensers for organic detergent that can be used up to a thousand times - and use tubs to collect water for cleaning instead of letting the tap run.

Chan's book is useful in the more general way of putting Hong Kong life into cultural context. Chan, a native Hong Konger and volunteer language teacher who lived in the United States for six years, said she wrote the book because "so many expats I've taught would ask questions and the questions were always the same." Her skills lie in explaining the mundane details of daily life so that even people who have lived in Hong Kong for decades can learn something from the book.

Take shoving. As anyone who has visited Hong Kong even briefly can attest, crowds on the streets push and jostle their way forward. In the ubiquitous skyscrapers, people surge into lifts, as the former British colony refers to its elevators, before those inside have had a chance to get out. The overall impression is of rudeness. But, as Chan explains, the phenomenon has its roots in the big population influxes from the mainland in the 1950s and 1960s. "Many arrived with nothing at all and yet still went on to establish thriving business," she writes. "To be diligent was the only way to survive the uncertainties of life at the time."

She discusses the combination language often used, throwing together Cantonese words with English slang. A fo van is a van carrying cargo; a call gei is a pager. Locals will say "Nog yiu check e-mail," or "I want to check e-mail," and "Nei sik jo lunch mai a," meaning, "Have you had lunch yet?"

She explains why one must never give a clock as a gift: The words in Cantonese, "sung jung," sounds like "saying farewell to a dying person."

What things sound like informs deep-held feelings about numbers, too. The overwhelming favorite is eight, but not, as it is sometimes said, because the number looks like an infinity sign sideways. In Cantonese, the number eight is pronounced baat, which makes people think of the word faat, meaning fortune. Another lucky number is three, pronounced saam in Cantonese, which is similar to another Chinese word saang, meaning robust. This also explains why some top hotels have telephone numbers featuring the number 38. Four is considered unlucky: It is pronounced sei, which sounds like another word meaning death.

Chan also offers real assistance at getting out of one of the classic awkward moments for newcomers to Hong Kong: a conversational impasse. A Chinese acquaintance might offer unsolicited advice or comments on appearance, offending the Westerner. The Westerner might confide all kinds of personal details and love-life sagas to a Chinese friend who finds it too soon in a friendship to even think of mentioning such matters.

The trick, Chan advises, is for both parties to be aware that the other means well, and that sensitivity to difference is the way to avoid offense.

Or take the hoary problem of yes and no. A Chinese might say "yes" to a Westerner's question to be polite or avoid a confrontation. The savvy Westerner will be able, with Chan's help, to deconstruct that response, realize that the true answer is "no," and say "yes" in reply to show that it is understood.

When you can do that, you are thinking like a Hong Konger.

Going Green in Hong Kong

By Catherine Touzard and Fabienne Malaval Dupré. 71 pages. Web site: www.goinggreenhk.com

Hong Kong Life & Culture

By Emily L.Y. Chan. Red Publish. 158 pages. Web site: www. red-publish.com

Vaudine England is a writer based in Hong Kong.