Canada's own acid rain scorecard isn't so clean

''Have you got a file on acid rain?'' The librarian raised her eyes, gave a bored sigh, and said, ''Is there any other kind of rain?''

Her response reflects the average person's ennui with the subject. Acid rain is hot stuff for reporters and politicians, but it appears to be a bit of a yawn for the general population.

There was quite a file on acid rain. Canadian newspapers seem to love the subject. It allows them to deliver a sanctimonious eco-lecture, along with some light American-bashing.

When a television crew sets out to film a piece on acid rain, you can be sure that the sternest part of the lecture will come while standing beside a grimy smokestack somewhere in the American Midwest. This, as we all know, is the source of the filthy fish-killing smog. For most of the acid rain, we are told, comes from the United States and is blown north to destroy Canadian lakes.

One newspaper story was headlined ''Acid Rain Burns Maple Syrup Industry: Expert.'' What an outrage, dirty American acid rain cutting at the national sweetener (at $22 a gallon it is hardly taking the place of sugar) and we have an expert to prove it. The experts were a farmer and a free-lance reporter from a small town in Quebec. There was a blight on the maple trees, and although they couldn't prove anything, it was a ''good bet acid rain is causing it.''

One Canadian politician has made a career of jumping on the acid rain bandwagon. He is John Roberts, the minister of the environment in the Liberal government in Ottawa. Mr. Roberts spends a lot of time in Washington trying to get the US to cut back on pollution and thus on acid rain.

Mr. Roberts has met with some success. A special commission in Washington is looking into acid rain. Reports are that it will recommend a 60 percent cut in sulfur dioxide emissions in the Eastern states. Those pollution restrictions are said to be much more than the Reagan administration has in mind.

There is industrial pollution. There is acid rain. It does kill lakes. But the information overkill on acid rain threatens to have exactly the opposite effect the propagandists aim for. It is difficult for any thinking Canadian to blame the whole mess on the Americans because Canadians do their share of polluting as well.

The industries of southern Ontario and the huge nickel smelters at Sudbury in northern Ontario all contribute to the pollution that is pouring down on Canada's lakes and rivers, to say nothing of its cities and its people.

The International Nickel smelter at Sudbury is Canada's No. 1 creator of acid rain because of the high sulfuric content of the ore it processes.

But Inco has been doing something about it. In the past 10 years it has cut its pollution in half. Canada's record as a whole is not that good.

Individual Canadians in ever-increasing numbers are switching from lead-free gasoline and buying regular leaded instead. It gives better engine performance and is cheaper.

The only problem is the big nozzle on leaded regular won't fit into the unleaded tank. Motorists are buying adaptors to beat that problem.

If Mr. Roberts' constituents are so concerned about acid rain, why are they burning fuel that pollutes more? And Ottawa emission standards set by Mr. Roberts' own department are not so stringent as those in the US, especially those in California.

Pollution creates acid rain. The pollutants rise from exhaust pipes and industrial chimneys and fall to earth as rain with a heavy acidic content.

Acid rain is said to hit the province of Ontario harder than others because it is directly north of the Ohio Valley, source of so much industrial pollution. But the government of Ontario itself is a major polluter. In the short term at least it refuses to do anything about it.

Ontario Hydro, the government-owned electric utility, actually increased its acid rain emissions over the past 10 years. It says it won't put in scrubbers to clean up the pollution because its customers would squawk. Ontario Hydro could cut its pollution in half in eight years, but the utility is phasing out coal generators and replacing them with nuclear power.

The pollution controls would mean higher utility costs, and Mr. Roberts' voters don't seem to want to put their money where their complaints are.

Because of the stand by Ontario Hydro, a Canadian conservation group recently criticized the lack of action by governments in Canada against acid rain. The Canadian Coalition on Acid Rain told a parliamentary hearing in Ottawa that the US was starting to take the issue seriously at last, while Canada was ''moving backward.''

The coalition criticized provincial governments, saying a big part of the problem is their reluctance to get tough with polluters. It said that Canadian credibility on the acid rain issue will be hard to maintain if major Canadian polluters are not stopped. Apart from Ontario Hydro, the group pointed a finger at Inco's operations at Sudbury and at Thompson, Manitoba.

Although a lot of money has been thrown at the problem of acid rain, it is still uncertain whether the administration in Washington sees it as a major problem.

A recent study suggested a novel way in which Americans and Canadians could get together to solve their mutual problem.

Since some acid rain is produced by coal-generated power plants in the US, Canadian provinces could offer American customers cut-rate electricity, produced by nonpolluting water power, shutting down the US coal plants and cutting down on acid rain. Canadian provinces, which control electric utilities, have yet to respond to that suggestion.