A challenge to the environmentalists; At the Eye of the Storm: James Watt and the Environmentalists, by Ron Arnold. Chicago: Regnery Gateway. 260 pp. $14.95.

The US public stands staunchly behind environmental protection laws. A recent Business Week poll found that over 80 percent of respondents opposed any loosening of the Clean Air or Clean Water Acts; 53 percent of participants in a 1978 survey by Resources for the Future agreed that ''protecting the environment is so important that requirements and standards cannot be too high.''

Ron Arnold doesn't dispute the depth of the environmental movement's support. He just feels that Americans ought to know better.

''We still tend to become environmentalists by a sort of 'cultural osmosis,' soaking up environmentalist sentiments without much critical thought,'' he writes. ''That can get us in a lot of trouble.''

Arnold is a Sierra Club dissident who says he fled the fold of environmentalism because of its ''excesses.'' His book, ''At the Eye of the Storm: James Watt and the Environmentalists,'' deals not so much with the controversial secretary of the interior as with the beliefs of environmentalism, a movement Arnold feels advocates preservation at any cost, doesn't care about economic realities, and probably prefers bears to men.

Watt, however, is the book's central personality, the vehicle used to carry its theme. Arnold contends that Watt is not the maniacal strip miner he's sometimes made out to be; rather, says Arnold, Reagan's secretary of the interior is a congenial, efficient nature lover, ''interesting and interested,'' who's been vilified by calculating environmentalists and an effete, liberal press. (One chapter is titled ''The Good, the True, and the Media.'')

Watt's deeply held pro-development beliefs, claims Arnold, reflect the true meaning of conservation - ''wise use of resources.'' Environmentalists, on the other hand, are pictured as land-grabbing ''preservationists'' who want to stop just about all development of natural resources.

Arnold quotes, approvingly, a Newsweek story of June 29, 1981: ''What environmentalists find so infuriating about Watt is not just that he disagrees with them, but that he challenges their most deeply held convictions. . . . He opposes them on their own terms, matching his idealism with theirs.''

Watt has undoubtedly suffered unfair slings: As pointed out in this book, the widely quoted Watt statement ''I do not know now how many future generations we can count on before the Lord returns,'' when seen in context, does not mean ''let's use all our oil now, because who knows what tomorrow will bring.''

But in ''Eye of the Storm'' Watt does no wrong. He tames the bureaucracy, tweaking the department until it runs more efficiently than a Japanese robot factory. He makes swift, straightforward decisions that have the force of right behind them, while environmentalists squeak and scurry off to hide. He still has time for his family. It all sounds a bit like ''Frank Merriwell Goes to the Interior Department.''

Then again, Ron Arnold is perfectly willing to admit he has a point of view. Half the book, in fact, is a straight critique of the modern US environmental movement. Arnold is disturbed by a number of intellectual trends he says are now entrenched in environmentalism, among them anti-technological attitudes (machines are evil), anti-civilization feelings (Thoreau was right), and a dark strain he calls ''anti-humanism'' (only man is vile).

One can quickly ascertain that Ron Arnold is not the sort of person one asks for a contribution to help save the snail darters. His book comes out of deep right field (it was underwritten by the conservative Free Congress Research and Education Foundation, a cousin of the equally conservative Heritage Foundation) but raises a timely question: how much environmentalism can we afford? When is the incremental gain in clean air or clean water not worth the millions of dollars it costs?

That is a political question, not an economic one. Liberal Democrats and conservative Republicans will look at the same environmental regulation, see the same cost and benefit analysis, and have different opinions as to whether the rule is wise. And, this book indirectly points out, environmental disputes are often complicated because each side often views itself as morally right as well as factually correct.

Well. At least we're sure whose side Ron Arnold is on.

''It may be a new idea that one can oppose environmentalists without opposing the environment, but it is a distinction worth considering,'' he concludes.