INTRODUCTION

Latitude effect and altitude effect are known regarding stable isotope ratio in atmosphere and water. If we made anthropogenic change for these it could have such effects. Currently scheduled passenger flights are restricted to bring any kind of liquid to inside cabin by passengers. Consequently collecting water for hand-wash (“In-flight water”) in lavatory in airplane is best way to such kind of experiments by scheduled passenger flights.

EXPERIMENTS

We made sampling in-flight water on UA890 from Los Angeles to Narita on JUL 19,2009 and on UA803 from Narita to Singapore on AUG 22,2009 and analyzed concentration of nitrate ion and nitrogen stable isotope ratio in nitrate.

DISCUSSION

During flight water tank of airplane is exposed by out side of atmosphere. Therefore concentration of nitrate ion was varied.　Comparing with almost same latitude,it had tendency that low altitude had high nitrogen stable isotope ratio and high altitude had low nitrogen stable isotope ratio. Comparing with same altitude, it had tendency that high latitude had low nitrogen stable isotope ratio and low latitude had high nitrogen stable isotope ratio.