It is true that there were some radioactive particles that did travel across the Pacific and reached North America about a week after the initial accident last year, but the amount of these particles and the levels of radiation were so low that it was not a health concern. The fact is that we are constantly exposed to background radiation from the ground, cosmic rays and other natural sources. The increase in radiation levels above background due to the Fukushima accident was so small that it could only be detected with very sophisticated instruments. At the present time, there is no radioactivity in Canada due to the Fukushima accident above normal background levels.
Health Canada has a system of radiation detectors placed across Canada. Some of the data (up to and including 2011) is available at the following website. The table on this page shows that there was no appreciable increase in radiation dose in the air after the Fukushima. Other sets of data for other cities and time periods are also available on the Health Canada website.
Again, because the amount of radioactive particles that reached Canada was so low, it was at the time of the accident and is still at the present time safe to consume food products from the Fraser Valley and from anywhere else in Canada.
If you are looking for some more hard numbers, there is some data in a report recently released by the World Health Organization entitled, “Preliminary Dose Estimation from the nuclear accident after the 2011 Great East Japan Earthquake and Tsunami.” This is a rather long report and is sometimes rather technical, but to summarize, radiation doses to countries neighboring Japan and in the rest of the world were less than 0.01 mSv, and usually significantly less than that (mSv are units of radiation measurement). Page 54 of the report provides some practical examples of how much radiation this compares to; for example, 0.01 mSv would be the same dose that one might receive from a 2 dental x-rays. A copy of that report can be found at the following link.
You had also asked about what can be done to protect ourselves and minimize our exposure from radiation. In the event of a radiological or nuclear emergency there are things that can be done, such as evacuation, sheltering in place, taking stable iodine and avoiding the consumption of contaminated water and food. However, none of these measures were required here in Canada and the time of the accident and are not necessary at the present time because, as was mentioned, the amount of radioactive particles that reached Canada was not a health concern and was hardly measurable above the natural background of radiation. More information on these topics can be provided if you are interested.
I hope that you find this information both helpful and reassuring. If you have any further questions, please do not hesitate to ask.