報告書番号

U88057

タイトル（和文）

石炭灰の体外排出と呼吸器系組織の形態学的変化

タイトル（英文）

LUNG CLEARANCE OF INHALED COAL FLY ASH PARTICLES AND MORPHOLOGICAL CHANGES OF RESPIRATORY ORGANS

概要 （図表や脚注は「報告書全文」に掲載しております）

本研究は，石炭灰を長期間暴露した動物（ゴールデンハムスター）を清浄空気に戻し，暴露停止後の石炭灰の体外排出と呼吸器系組織の形態学的変化を明らかにする目的で行った。結合組織内の石炭灰を貪食したマクロファージ数と縦隔リンパ節への石炭灰の蓄積は，暴露停止後でも増加し，その量は暴露停止前の濃度と暴露期間に依存していた。しかし，石炭灰の体外排出は肺胞マクロファージと好中球によって継続的に行われ，肺内に沈着した石炭灰は経時的に減少した。貪食細胞が集積した肺胞では２型上皮細胞の増殖が起こったが，集積の減少に伴い軽減，あるいは消失した。また，呼吸器系組織以外の臓器への石炭灰の移動は認められず，これらの臓器に石炭灰吸収による病理組織学的変化も認められなかった。

概要 （英文）

FOUR GROUPS OF MALE GOLDEN HAMSTERS WERE EXPOSED TO 0(FILTERED-AIR ONLY), 1 AND 20 MG/CUBE M OF COAL FLY ASH(FA) FOR 90 DAYS, AND 2 MG/M3 FOR 180 DAYS (20HR/DAY,7DAYS/WEEK),RESPECTIVELY.ANIMALS WERE SACRIFICED AT THE END OF EXPOSURE AND AT 7,30,90,AND 180 DAYS AFTER THE CESSATION OF EXPOSURE. THE GROSS OBSERVATIONS SHOWED THAT BLACK PIGMENTS IN THE LUNG PARENCHYMA OF EACH EXPOSED-ANIMALS WERE ELIMINATED GRADUALLY IN RECOVERY PERIOD. HYPERTROPHY AND HYPERPLASIA OF TYPE 2 EPITHELIAL CELLS WERE FREQUENTLY OBSERVED IN ALVEOLAR REGION SURROUNDING THE ACCUMULATIONS OF PHAGOCYTES. THESE HISTOLOGICAL CHANGES WERE OBSERVED THROUGHOUT THE LONG RECOVERY PERIOD,HOWEVER,THOSE BECAME MILD OR DISAPPEARED WITH RECOVERY TIME. DEPOSITION OF FA PARTICLES IN MEDIASTINAL LYMPH NODES (MLN) INCREASED WITH TIME,EVEN IN THE RECOVERY PERIOD. IN MLNS AT 180 DAYS AFTER 180 DAYS OF EXPOSURE TO 2 MG/CUBE M OF FAAND AT 90 DAYS AFTER 90 DAYS OF EXPOSURE TO 20 MG/CUBE M OF FA,RETROTHELIAL CELLS ENGULFED NUMEROUS FINE PARTICLES. FA PARTICLE DEPOSITION AND HISTOPATHOLOGICAL CHANGES IN OTHER ORGANS WERE NOT OBSERVED THROUGHOUT THE RECOVERY PERIOD IN THIS EXPERIMENT.

報告者

キーワード