Archive for the ‘General (等)’ category

Radiation in the Mountains: Q & A

April 8, 2012

The following is a translation of an interview conducted with Katsumi Shozugawa, an Associate Professor and Researcher at The University of Tokyo Graduate School of Arts and Sciences, which appeared in the January 2012 issue of Yama-To-Keikoku Magazine, a monthly outdoor magazine published in Japanese. This translation has been done with the consent of the magazine and should be of interest to hikers in Japan who can’t read Japanese. The opinions expressed here reflect those of Mr. Shozugawa and not of Yama-to-Keikoku or Hiking in Japan.

Question 1:  Aren’t the radiation levels in mountains streams high?

Recently we tested Karasugawa river (on Mt. Adatara) and found that above Karasugawa bridge radiation levels varied from 0.05 microsieverts/hour* to 0.312 microsierverts/hour. However, at the bridge level at the river embankment the readings were 0.184 and decreased to 0.176 at the surface of the river. From this we can see that because of wind and rain, soil or leaves containing radioactive cesium have been transported, the speed of which varies according to region. For this reason, over time the areas which have previously had a high air dose rate can fluctuate. In this way, due to the fact that environmental conditions are constantly changing, it’s difficult to accurately predict whether mountain streams have high or low levels of radiation.

Question 2: Are there any radiation hotspots in the mountains?

Yes there are.  This time approximately 0.02 microsieverts/hour was observed on a forest road at the edge of a gully. We also measured at the base of the gully and found readings nearly double what was found at the forest road. When you take a rest during your hike, it’s best to avoid these types of gullies where mud and runoff have accumulated, as well as areas with large piles of rain-transported foliage.

Question 3: Is it ok to take home fallen leaves or soil from the mountains?

It has been reported in the news that fallen leaves have contained a high level of contamination, but if you want to take home one leaf as a memento, it shouldn’t be a problem. However, you should refrain from taking away large quantities of foliage as well as rustling through large piles of fallen leaves.

Question 4: Since the snow season has arrived, what kind of radioactive effect will there be?

Since snow will cover the land, you won’t need to worry about flying radioactive particles or the risk of internal radiation exposure. In addition, snow has a shielding effect against radiation, depending on the density of the snow. We can expect a 30 to 40% reduction in radioactive emissions in compacted snow (such as those in groomed ski resorts). If the snow has accumulated over 1 meter in depth, however, then it is thought there will be a full shielding effect. Since fresh snowfall has a low risk of contamination, it should not be a problem to drink snowmelt.

Question 5: Is it ok to gather and eat mushrooms from the mountains?

There hasn’t been adequate testing, so you should not eat wild mushrooms gathered in the forest. In the mountains, there is a high likelihood for radioactive contamination of kinoko mushrooms, chestnuts, freshwater fish, river crabs, wild boar and such. Since the mountainous landscape is extremely diverse, even small changes in location can result in varying levels of contamination. Viewing wild mushrooms is ok, but you should refrain from picking and eating them.

Question 6: What should you do if you fall and injure yourself, getting dirt into your open wound?

There is a danger that radioactive materials attached to soil could directly enter your bloodstream, which is thought to be more dangerous than direct inhalation or drinking contaminated water. In order to decrease internal radiation exposure, wounds should be washed with water as quickly as possible. After washing, the wound should be wrapped with a bandage in order to prevent dust and dirt from reentering the wound. It is safer to use a hydrocolloid dressing (such as a kizu power pad) to help keep air out.

Question 7:  Is it safe to drink from the mountain streams and rivers?

Since radioactive cesium has a positive charge, it is easily bonded to clay particles containing a negative charge. Once this happens, it is thought that there is a low chance of these bound particles dissolving in water. This being the case, as long as Iodine 131 is not emitted, there shouldn’t be a worry of contamination of underground water sources. Since there is a danger of contamination in the dirt riverbeds, you should avoid ingesting dirt particles when drinking water from streams. Instead, water should be filtered with a portable water filter.

Question 8: Are there any precautions you should take after finishing your hike?

At the trailhead, please clean off all dirt that has stuck to hiking boots, clothing, and your backpack. When doing this, be sure not to inhale any of the brushed off dust. Since volcanic soil can contain especially strong acids and alkaline metals, you should wash off your boots immediately after finishing your hike. If you don’t, the rubber and leather can deteriorate rather quickly. Regardless of whether there is radioactive contamination or not, it’s my recommendation to promptly clean off everything before returning home.

*Read here for more information regarding measurements of radiation.

A closer look at Hiking in Japan, 2nd edition

September 7, 2009

This guidebook is now out-of-print. The replacement book, entitled Best Day Hikes Japan, is slated for release on March 2nd, 2021.

LP cover

Changes: Despite the obvious aesthetic changes which I will cover a little later, I think it’s most prudent to start with the content changes. In line with other guidebook updates, the publishers have kept most of the existing print intact, so those of you looking for new hikes not mentioned in the first edition may be a bit disappointed. However, extra information has been added in the ‘extra hikes’ section (currently renamed as ‘more hikes’). For instance, there’s an alternate trail leading off from Yari-ga-take towards Otensho-dake that wasn’t mentioned in the first edition. This is a good chance to view the Hotaka range from a different perspective. On the Tsurugi-san hike in Shikoku there are a couple of alternative routes that weren’t mentioned before, including a descent down the northern face of Miune. Hokkaido dwellers will be happy to note that Shari-dake has been added to the list of extra hikes. The Kansai section has been completely reworked, and two of the most problematic hikes (Yura-gawa and Kunimi-dake) have been moved from the main section to the ‘more hikes’ section.

The ‘easy-medium-difficult’ rating system from the first edition has been renamed ‘easy-moderate-demanding.’ I’m not sure if it’ll be any easier for newcomers to grasp the physical exertion required for the hikes, but each multi-day hike listed in the new edition now includes expected hiking time, distance, and vertical elevation gains (hooray!). A new section in the front of the book has been added called ‘History and Culture of Hiking’, which includes information about the Hyakumeizan, pilgrimages, and the role of religion in the mountains. Most of this information was scattered through the first edition but has now been consolidated into one easy-to-reference section.

Now let’s move onto the appearance. The green color scheme of the first edition has been replaced by vibrant tones of red. The maps also reflect this new design, and are much easier to read and decipher than the original ones. Rumor has it you’ll be able to pore over your maps under a full moon without a torch!

Old Map

Old Map

New Map

New Map

All of the photographs have been relocated to a section at the very beginning of the guidebook. This is good news for those of you who had to tear out the pictures in the old book that were always placed in annoying locations. Most of the general stuff that appears in every Lonely Planet guidebook (Health and Safety, Getting Around, et al) has been pushed to the very back of the new edition. This is great news for those sharp souls who noticed that the very first hike in the 1st edition didn’t begin until page 112! The first hike now begins on page 61 (phew.)

The verdict: So, now that you’re familiar with what to expect, the million dollar question would have to be whether or not to purchase the new edition. Those of you who don’t have the first edition but are truly interested in getting into the outdoors should definitely consider purchasing the update. If you’ve got the first edition and have done over 90% of the hikes contained within, then I wouldn’t put it too high on your priority list. However, if you’ve been served well by the first edition and have yet to check out some of the hikes, then it might be worth your while to pick up the new book. If you’re not too keen on shelling out the 2700 yen for the book but are still interested in adding it to your collection, just remember that you could always ask one of your friends or family members to buy it for your as a birthday/graduation/holiday present. Or, if you want to get really creative as I did, then you can convince your private student to give it to you in lieu of a lesson payment.

Interview with Craig Mclachlan

May 10, 2009

Here is a recent interview I did with Lonely Planet author Craig Mclachlan for Kansai Scene magazine.


Guidebook update

March 22, 2009

Yes, the rumors are true. Lonely Planet is finally updating their Hiking in Japan guidebook.


This time around, Craig McLachlan has teamed up with Richard Ryall and David Joll for a comprehensive overhaul of the 1st edition. Unfortunately, there are no new hikes in the updated 2nd edition, but I still think it’s worth adding to your collection. Also, if you’re thinking about buying the 1st edition, you might want to wait a month and buy the new one. The release date will be July 2009 (pushed back from an original release date in May). Although Lonely Planet has not officially announced the update, the information gathered here comes from two reliable sources: 1) (do a search for Hiking in Japan 2nd edition) 2) Personal communication with the lead author. (By the way, I don’t work for Lonely Planet and I’m not receiving any royalties from the sales of this guidebook).