Microscopic analysis of chromium accumulation in the bronchi and lung of chromate workers.
BACKGROUND
It is known that chromium is an inhaled carcinogen and an important risk factor in the development of lung carcinoma.


METHODS
The authors used a microscopic X-ray fluorescence analyzer with transmitted X-ray mapping imaging (Horiba, Kyoto, Japan) to measure the accumulation of chromium in 10 resected lung tissue specimens and 90 biopsy specimens from chromate workers.


RESULTS
The maximum chromium accumulation (mean +/- standard deviation) in 10 resected lung tissue specimens was 197 +/- 238 counts per second (cps)/mili ampere (mA) (range, 4-649 cps/mA). Chromium accumulation was scattered in six tissue specimens and diffuse in one specimen. Chromium accumulation in the proximal bronchi was less than in the bronchioles or subpleural regions of the lung. Chromium accumulation was detectable in 63 (70%) of 90 biopsy specimens, and the mean accumulation was 6.5 +/- 9.2 cps/mA (range, 0-46.5 cps/mA). Chromium detected in bronchial tissue specimens was deposited in the bronchial stroma but not in the epithelium. The maximum chromium accumulations in dysplasic (n = 3), squamous metaplastic (n = 10), and normal bronchial epithelia (n = 9) in chromate workers and in normal bronchial epithelia (n = 3) in non-chromate workers were 20.2 +/- 5.4, 18.3 +/- 12.2, 13.2 +/- 13.4, and 3.0 +/- 1.8 cps/mA, respectively. The amount of chromium accumulation significantly increased according to the progression of malignant change of the bronchial epithelium (P = 0.003).


CONCLUSIONS
Previous studies found that lung carcinoma with chromate exposure exhibited a variety of genetic abnormalities. Considering genetic aberrations and chromium accumulation in these premalignant lesions is useful for elucidating the process of carcinogenesis in chromium-induced lung carcinoma.
Kondo
Kazuya
K
Department of Oncological and Regenerative Surgery, School of Medicine, University of Tokushima, Tokushima, Japan. kondo@clin.med.tokushima-u.ac.jp
Takahashi
Yuji
Y
Ishikawa
Sumiyo
S
Uchihara
Hiroshi
H
Hirose
Yukiko
Y
Yoshizawa
Kiyoshi
K
Tsuyuguchi
Masaru
M
Takizawa
Hiromitsu
H
Miyoshi
Takanori
T
Sakiyama
Shoji
S
Monden
Yasumasa
Y
D000328:Adult; D000368:Aged; D001980:Bronchi / Q000737:chemistry*; D002277:Carcinoma / Q000209:etiology*; D002840:Chromates / Q000633:toxicity*; D002857:Chromium / Q000032:analysis / Q000493:pharmacokinetics*; D006801:Humans; D019570:Inhalation Exposure; D008175:Lung Neoplasms / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D011230:Precancerous Conditions / Q000209:etiology* / Q000473:pathology; D018570:Risk Assessment; D013052:Spectrometry, X-Ray Emission
D002840:Chromates; D002857:Chromium