報告書番号

U86017

タイトル（和文）

石炭灰吸入による実験動物の生体反応－慢性吸入実験－

タイトル（英文）

INHALATION EXPOSURE OF COAL FLY ASH TO LABORATORY ANIMALS-CHRONIC INHALATION STUDY OF GOLDEN HAMSTERS-

概要 （図表や脚注は「報告書全文」に掲載しております）

２ｍｇ／ｍ３の濃度の石炭灰を１８０日間（１日２０時間，週７日間）ゴールデンハムスターに連続吸入させる実験を行った。体重，呼吸数の加令に伴う変化は暴露・対照両群ともに同様で，血液・血清化学的検査結果においても，石炭灰の吸入による変化は長期間の暴露後においても認められなかった。呼吸器系組織では肺内に沈着した石炭灰を貧食した肺胞マクロファージが血管，細気管支，および胸膜下の肺胞に集積する傾向がみられ，この度合いは暴露の経過とともに強まった。このような部位の肺胞は構成する上皮細胞の腫大・増大がみられたが，肺胞中隔の肥厚や繊維化の進行はみられなかった。また，暴露した石炭灰は気管周囲の縦隔リンパ節の大食細胞内にも観察された。しかし，他の臓器には吸入による変化は認められず，また，石炭灰粒子もこれらの臓器で観察されなかった。

概要 （英文）

INHALATION EFFECTS OF COAL FLY ASH WERE INVESTIGATED USING YOUNG ADULT MALE GOLDEN HAMSTERS(MESOCRICETUS AURATUS). ANIMALS WERE FORCED TO INHALE THE COAL FLY ASH FOR 180 DAYS IN THE EXPOSURE CHAMBER. AT THE CONCENTRATION OF 2MG/CUBE M,20 HR/DAY,7 DAY/WEEK. BODY WEIGHT AND FREQUENCIES OF BREATHING WERE NOT STATISTICALLY DIFFERENT BETWEEN THE EXPOSED-AND THE CONTROL-GROUP AT ANY SACRIFICE TIME. RESULTS OF HEMATOLOGY AND BLOOD SERUM CHEMISTRY AT 30,60,90 AND 180 DAYS OF EXPOSURE SEEMED TO HAVE SHOWN NO HEALTH EFFECTS. RESPIRATORY ORGANS AND OTHER ORGANS WERE EXAMINED PATHOLOGICALLY. AFTER 30 DAYS OF EXPOSURE,SOME SMALL BLACK SPOTS OF ABOUT 0.5 TO 1 MM IN DIAMETER WERE SEEN IN LUNGS,AND AFTER 60 DAYS OF INHALATION MORE SMALL SPOTS WERE ABLE TO BE OBSERVED IN THE MEDIASTINAL LYMPH NODES OF EXPOSED-ANIMALS. THESE BLACK SPOTS IN THE LUNGS INCREASED IN NUMBER AND INCREASED IN DIAMETER IN MEDIASTINAL LYMPH NODES WITH THE DURATION OF INHALATION PERIODS. HISTOPATHOLOGICALLY,THESE BLACK SPOTS IN LUNG CONSISTED OF A NUMBER OF THE ALVEOLAR MACROPHAGES LADEN A LOT OF INHALED PARTICLES. ALVEOLAR MACROPHAGES INGESTED MANY INHALED PARTICLES IN ALVEOLI AND TENDED TO ACCUMMULATE INALVEOLI AROUND VENULES,RESPIRATORY AND TERMINAL BRONCHIOLES,AND IN ALVEOLI JUST INSIDE THE PLEURA VISCERALIS. ALVEOLAR EPITHELIUM WHICH COMPOSED OF SUCH SPACES MAINLY CONSISTED OF TYPE 2 EPITHELIAL CELLS AND THESE ACCUMMULATED MACROPHAGES LOCATED CLOSELY TO THESE EPITHELIAL CELLS. IN THE MEDIASTINAL LYMPH NODES OF EXPOSED-ANIMALS,MACROPHAGES MAINLY IN MEDULLA OF PULP AND IN LYMPHATIC SINUS INGESTED A NUMBER OF FLY ASH PARTICLES. INHALED PARTICLES WERE NOT OBSERVED IN OTHER ORGANS EXCEPT RESPIRATORY ORGANS AND THERE WERE NO HISTOPATHOLOGIC CHANGES IN OTHER ORGANS OF ALL EXPOSED-HAMSTERS AT ANY SACRIFICE TIME.

報告者

キーワード