沙漠研究 22-1, 167 -170 (2012 )"ICAL 1 / DT X"

Journal of Arid Land Studies－Refereed Paper－

Outbreak of Foot-and-Mouth Disease in Miyazaki from March to July 2010
- Effect of Yellow Sand and Local Surface Wind Taichi MAKI*1), Hiroko ISODA1), Takahiro MORIO1), Parida YAMADA1),
Tamao HATTA2), Mingyuan DU3) and Kenji WAKIMIZU4)
Abstract: The transport of foot-and-mouth disease (FMD) virus (FMDV) and the appearance of FMD based on yellow sandtransported by global winds high in the atmosphere, and the spread of FMD diffused by local winds of the surface air layer based via
particles adhered FMDV were investigated concerning to climatic properties of global wind about yellow sand and of local wind inMiyazaki. FMD appeared and spread in Miyazaki from March to July, and 289,000 domestic animals was slaughter. It is deeply
related between transportation of FMDV by yellow sand, and appearance and spread of FMDV by local winds of monsoon. Japan
has to predict the transport of yellow sand adhered with FMDV and bio-aerosol, and to protect against various diseases at any time.
Key Words: Desert, Foot-and-mouth disease, Global and local winds, Miyazaki, Yellow sand

1. Introduction
A report entitled “Clarification on the global circulations ofyellow sand or Kosa, and cross-border air pollutants andcountermeasure of their effects” was published by the Science
Council of Japan on February 25, 2010 (Maki et al., 2010a).
The report describes the relationship between yellow sand andfoot-and-mouth disease (FMD) virus (FMDV). After theappearance of FMD in China on December 30, 2009 and in
Korea on January 2, 2010, interest in FMD increased in Japan.
This paper discusses the transport of FMDV and theappearance of FMD based on yellow sand (Fig. 1) transported
by global winds high in the atmosphere, and the spread ofFMD diffused by local winds of the surface air layer based via
particles to which FMDV adhered (Maki, 2010; Maki et al.,2010b).

2.2. Cause of the first appearance of FMD and its spread
The first informal FMD infection in livestock was detectedin buffalo on March 26, 2010, at Tsuno Town in Miyazaki
Prefecture, Kyushu, Japan. But the first formal infection ofthree cattle; cow and bull was recognized at Tsuno on April 20.

2. Methods and Results
2.1. Relationship between yellow sand and the appearanceof FMD overseas
FMD was spread out almost all across Asia in 2010. EastAsia, including China, Mongolia, Korea, Taiwan, and Hong
Kong, was struck mainly by FMD of O and A types. In Japan,
only O type was found in 43 and 292 cases until on May 7 andJuly 4, 2010, respectively. The O type was found on March
14 in Gansu and on March 25, 2010 in Shanxi, China. It ispresumed that the origin of FMDV spread on March 25 inShanxi, China and on March 26 in Japan is based on theFMDV found on March 14, 2010, in Gansu, China.

Fig. 1. Yellow sands flying up from China and falling down to Japan.
(A) Outbreak of yellow sand with wind erosion at Turpan, China.
(B) Yellow sand observed at Kyushu University in Fukuoka, Japan.

* Corresponding Author: maki.taichi.fe@u.tsukuba.ac.jp
1-1-1, Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
1) Alliance of Research on North Africa, University of Tsukuba

3) National Institute for Agro-Environmental Sciences

2) Japan International Research Center for Agricultural Sciences4) Faculty of Agriculture, Kyushu University

The suspected infection of six cattle was recognized on April
21 at Tsuno and that of five pigs on April 27 at Kawaminami
Town. After that, the number of infected livestock increased
very rapidly, and FMD spread out widely in Miyazaki. The
durations of FMDV incubation are 6.2 days for cattle and 10.6
days for pig according to Newspaper of Agriculture in 2010, or
2 to 8 days in Ministry of Agriculture, Forestry and Fisheries.
If the first infection occurred on March 26, the cause ofFMD is presumed to be yellow sand blown into Japan from theGobi Desert of northern and central China on March 16 withrain on March 15 and/or 21 with rain March 20, 2010 by
WNW to W wind directions, based on certainly FMD
appeared in Gansu on March 14, 2010. Yellow sand on
March 21 was observed to be arriving in very strong scales andacross a wide area, at 63 out of 67 points in Japan, and thearrival of the sand continued for a long time. The yellow
sand observed in Japan in 2010 remained at a fairly high levelfor 30 days and 381 point-days in 67 Observatory until May 31,
2010.
According to the average appearance rate (day) by month,
the yellow sand season is from March to May.
According to variation of precipitation; rain and dust storm;
dust and yellow sand at Dunhuang in northwest China, climateof summer rainy season is from June to August, and mainyellow sand season is from March to May to similar in Japan.
2.3. Spread after the first appearance of FMD
There are two means by which FMD has spread to Japan.
One type caused the first appearance, on March 26, and theother type caused later appearances. The authors concluded
that the first appearance was based on yellow sand transported
a long distance and that the virus was not spread by directcontact with FMDV carried by humans, nor was it conveyed
through feed (straw). Rather, the first appearance of FMDV
is attributable to the virus adhering to yellow sand particles
transported long distances by high-altitude winds.
Although we cannot exclude the possibility of infection
and diffusion from Tsuno to other areas in Miyazaki is byhuman movement, feed, and so on, it is rather certain that thevirus was based on soil-sand particles and fine mattertransported by local winds, because the same virus, the O type,
was found around a certain area at the same time.
2.4. Meteorological reason for yellow sand blown intoMiyazaki
It is interesting that FMD appeared only in Miyazaki but
not at other places. The reasons are clearly that Miyazaki islocated in the leeward wind area of the Kyushu Mountains, anarea that has frequent clear and fine days in winter and spring
and that a northwesterly wind also blows frequently. Ingeneral, on the leeward side of a mountain there are relatively
many fine, dry days as a result of Foehn or Bora winds, similar
to a phenomenon in desert areas on the leeward side of a highmountain. In both cases, a downward wind reaches theground from high altitudes. Thus, more yellow sand falls
there than elsewhere.
In May, 2010, as in the middle of the period spread of
FMD and in the last month of the yellow sand season, yellow
sand was investigated in seven prefectures on Kyushu Island;
Nagasaki (N), Saga (S), Fukuoka (F), Oita (O), Kumamoto(Ku), Miyazaki (M), and Kagoshima (Ka). The total numberof observation was N 1, S 5, F 3, Ku 8, O 4, M 5 and Ka 4.
Kumamoto of 8 was probably affected by aircontamination, and Miyazaki and Saga of same 5 followed.
For the reasons explained above, yellow sand is found as pretty
high levels in Miyazaki despite the high amount ofprecipitation in south Kyushu. Differences in the amount ofyellow sand between these areas were found even in May 2010,for example.
2.5. Possibility of FMDV transportation by yellow sand
It is said that FMDV is quickly destroyed under thefollowing conditions; ambient temperature exceeding 50°C,
relative humidity below 60%, and pH above 10 or below than
6. However, as yellow sand particles have rough surfaces andsometimes crack (Fig. 2A), the virus adhering to a particle cansurvive despite these conditions. If it rains occasionally, theparticle surface with the virus would be covered with clay.
The environmental conditions under which the virus
survives (below 50°C temperature, above 60% humidity, pH
6-10) can easily persist for a few days. Even if it does notrain, the virus could be alive in rough particles and deep inside
particles without a problem, indeed with a fairly highprobability. Yellow sand can fly to Japan in 2 to 3 days fromGobi Desert and Taklimakan Desert or, if it originates from theLoess Plateau, in only 1 day. Of course, the total probabilityof appearance of FMD is low, however the possibility stillremains.
Before flying yellow sand from the surface at the blowing
sand area, it sometimes rains. If there are rainclouds, the air issaturated with vapor or water and the sand particles are caught
in rain drops. Thus FMDV lands in Japan via sand particles
and the rain. Yellow rain is found and sedimentation ofyellow sand is also recognized. Livestock drink fallen
rainwater and are suffered by FMDV. Although theprobability is low, FMDV infection through this route ispossible. As yellow sand in the presence of a passing cold
front has a high chance of encountering vapor because that it
sometimes rains, i.e., 2 cases before yellow sand and the living
virus can land in Japan.

(A)(B)supposed the source of FMDV in spring at Miyazaki City inKyushu and at Honbetsu Town in Hokkaido in Japan, as wellas in Korea and far-eastern Russia. The reason is consideredthat FMD is based on the general circulation of yellow sandtransportation from China and Mongolia because that it was
found in same yellow sand season of spring. FMD appearedon March 12 at Miyazaki is presumably attributed to yellow
sand observed at Miyazaki Observatory on March 7, and FMD
appeared on May 11 at Honbetsu in Hokkaido is to yellow
sand observed on April 8 at Asahikawa Observatory.
Although spread of FDM was finished just in Miyazaki on
this time, dust and yellow sand come overseas by long distancetransportation. As FMDV falls continuously to earth fromoverseas, it is necessary to protect in anytime.

3. Discussions
Fig. 2. Yellow sands surveyed by electron microscope (Hatta et al.,2009). (A) Surface structure of yellow sand. (B) Fine matter(Gp; gypsum) adhered on quart surface.

The flight of yellow sand from China depends on the typeof wind blowing, high or low pressure, cold or warm front,
topography, and so on. That is, these factors can determine
not only from what region and what place the sand lifts offfrom the surface, but also the route the sand flies and where itlands. The frequency with which contaminated sand has
fallen in Miyazaki is interesting, but final result remains
unclear.
Yellow sand fallen in Japan sometimes consists of gypsum
and ammonium sulphate adhered on yellow sand (Fig. 2B).
The chemical reaction does not occur on the ground surface,
but happens rather high in the sky under the conditions of highhumidity and near-neutral pH (Hatta et al., 2009). The
alkalinity of yellow sand and acid rain by air contamination
can be near neutral. In this environment, the virus remains
alive.
In conclusion, if the first appearance of FMDV is brought
about by yellow sand at Tsuno, and then the further spread of
the virus is generally affected by local winds, based on the very
high possibility of surface winds.
2.6. FMD in Miyazaki and Hokkaido spread in 2000
Yellow sand blows from China to Korea and Japan, passes
over the Pacific Ocean to the USA and Canada, crosses theAtlantic Ocean to Europe with the portion of the sand fallingon the earth surface, and returns to China, and begins the cycle
again as a global transportation. It circles the earth in 12 to 13
days (Uno, 2009).
In 2000, yellow sand from China and Mongolia is also

3.1. Spread of FMD in Miyazaki
Here we discuss the appearance and spread of FMD.
FMD was actually recognized at Tsuno, Miyazaki, on April 20,
but it was presumed by precise inspection that the first animal
infected with FMDV was found on March 26. The outbreakspread from Tsuno to Kawaminami. It was said that thecauses of this spread were unclear finally. However, theauthors predict that they probably did not include thetransportation of livestock, feed, human activity, cars, and soon. For meteorological researchers, the exclusions of an
atmospheric cause by virus specialists on the appearance of
infection in the first and on the spread of infection after
appearance are difficult to comprehend.
About FMD infection via the air, infected livestock caneasily spread the virus through their exhalations, which containsmall floating particles of solids and liquids in the aerosol
blown out from a trachea or windpipe of throat (Ono, 2010).
According to the US Department of Agriculture shown in
Figure 3, 22% of cases of FMD infection are spread by windand flying birds. The spread by FMDV floating in the wind
is understandable in the case of Miyazaki. It is possible that
FMDV was transported in the wind on dust, soil-sand particles,
shed fur, and skin from livestock, air pollutants, and SPM;
suspended particulate matter.
FMD was transferred from north to south as an order fromTsuno to Kawaminami, Takanabe, Shintomi, and Miyazaki
from March to May by northwest wind. The direction isfrom north to south and not to east because the border of eastside is sea. Ebino is not included in this order because
infected cattle were transported there from other areas. The
infection was clearly transferred by the northwesterly wind in
spring, and after that, from May to July, it was mainly based on
the change to monsoon season by the southeast wind, which

Contaminated meatand its abandoned
汚染肉やその廃棄物
matterWind and風や渡り鳥
flying birds
Movement of
家畜の移動
livestock
Movement ofcontaminatedmatter
汚染物や人and humanWild
animals
野生生物など010203040506070

Infection rate (%) oforigin of foot-and-mouth disease for livestock
家畜などの動物への感染源比率(%)・(UDSA;Asahi Newspaper, June 1, 2010)（米農務省まとめ、朝日新聞、2010.6.1）

Fig. 3. Infection rate (%) of origin of foot-and-mouth disease forlivestock (UDSA; Asahi Newspaper, June 1, 2010).

spread the virus to Kijyo, Kunitomi, Saito, Miyakonojyo, andHyuga, enlarging the area of infection. The directions andtransfer of infection from March to July is thus clarified by theusual wind speed and wind directions.
3.2. Investigation of yellow sand adhered with FMD
The authors investigated three places (Okinawa, Fukuoka,and Tsukuba) where yellow sand samples were obtained by ahigh-volume air sampler. It is presumed that the evidences of
FMDV were detected in all in three places (Shi et al., 2009).
The method used was a DNA evaluation technique, thus it isunclear whether the detected virus was alive or dead because oftraces of FMDV.
The analysis points to a high possibility that FMDV wasblown from China and Mongolia, by virtue of the fact that itwas detected in yellow sand at all three observation points
covering a wide area of Japan. In fact, active FMDV wasfound in 2010, and FMD was spread to Miyazaki. How doyou think about the relation between the active FMD inMiyazaki, and the situation from appearance to spread ofFMD?
We have to predict the transport of FMDV-adhering yellow
sand or bio-aerosol, and to protect against FMD and various
other diseases at all times.

4. Conclusions
The results of our study of the appearance and spread offoot-and-mouth disease are as follows: 1) It is deeply related
between transportation of active virus by yellow sand, andappearance and spread of foot-and-mouth disease virus by
local winds in Miyazaki. 2) As the first infected livestock by
foot-and-mouth disease virus were detected on March 26, 2010,in Miyazaki, the cause is presumed to be yellow sand blown
from Gansu, China on March 14 and landing in Miyazaki,
Japan on March 16 and/or 21, 2010. 3) After the first
appearance of foot-and-mouth disease, it is certain that localwinds further spread the virus on soil-sand particles and finematter, because the same O type of virus was found in a wide
area at the same time. 4) The virus was clearly spread bynorthwesterly winds, because the infections spread from northto south from March to May. The direction of infection wasclarified by the wind direction, which changed to a southeast
direction from May to July. 5) As Miyazaki is located in theleeward wind area of the Kyushu Mountains, it has frequent
clear or fine days in spring, and a northwesterly wind blows
down from high altitudes, similar to the leeward phenomenon
in deserts. The amount of yellow sand is rather greater in thisarea despite the high amount of rain this area receives in spring.
6) It is presumed that, in 2000, the infection detected on March
12 in Miyazaki is attributable to the yellow sand observed on
March 7 in Miyazaki, and that the infection detected on May
11 at Honbetsu, Hokkaido is to the yellow sand observed on
April 8 at Asahikawa, Hokkaido. 7) We have to predict thetransport of yellow sand adhered with foot-and-mouth diseasevirus and bio-aerosol, and be prepared to protect against
various diseases at any time.

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