Two Cases of Methemoglobinemia Induced by the Exposure to Nitrobenzene and Aniline
- PDF / 677,405 Bytes
- 7 Pages / 595.276 x 793.701 pts Page_size
- 93 Downloads / 116 Views
CASE REPORT
Open Access
Two Cases of Methemoglobinemia Induced by the Exposure to Nitrobenzene and Aniline Chang Hwan Lee1, Soo Hyeon Kim1, Do Hyung Kwon1, Keun Ho Jang1, Yong Hoon Chung2 and Jai Dong Moon1*
Abstract Objective: To report two cases of methemoglobinemia induced by inhaled nitrobenzene and dermally absorbed aniline. Methods: We have evaluated a 37-year-old male worker exposed to nitrobenzene by inhalation while conducting maintenance job of mononitrobenzene pump and a 25-year-old male worker exposed dermally to aniline while unloading. Results: The first case is a 37-year-old male exposed to nitrobenzene. His blood methemoglobin concentration level was initially 19.8%, and chest X-ray was normal. After oxygen therapy, the blood methemoglobin concentration level decreased to 2.1%, and the symptoms were alleviated. The second case is a 25-year-old male exposed dermally to aniline. His chest X-ray was normal, but blood methemoglobin concentration level reached maximally 46.8%. He was treated with methylene blue due to relatively high blood methemoglobin level. Gradually after the treatment, his methemoglobin concentration level was normalized to 0.8% and simultaneously symptoms were resolved. Conclusions: After the thorough exposure investigations and medical evaluations, we have concluded that these cases were methemoglobinemia induced by occupational exposure to nitrobenzene and aniline. We suggest that businesses which handle methemoglobinemia-causing substances control the engineering process strictly, implement periodic screening, and establish emergency patient management system. Keywords: Nitrobenzene, Aniline, Methemoglobinemia
Background Methemoglobin (MetHb) is a modified form of normal hemoglobin where Fe2+ (ferrous ion) is oxidized into Fe3+ (ferric ion). MetHb cannot bind with oxygen, and hence it cannot carry oxygen. The human body can tolerate a very small amount (less than 1%) of MetHb, but a higher level is likely to cause methemoglobinemia [1-4]. Methemoglobinemia can be both inherited and acquired. Methemoglobinemia is commonly caused by exposure to medical substances, such as benzocaine and dapsone, that oxidize hemoglobin to MetHb; exhaust fumes from internal combustion engines; herbicides and pesticides; and chemicals, such as nitrobenzene and aniline [5-11]. Nitrobenzene and aniline are typical aromatic nitro compounds and aromatic amino compounds that cause methemoglobinemia. * Correspondence: [email protected] 1 Department of Occupational and Environmental Medicine, Chonnam National University Hwasun Hospital, Hwasun, Korea Full list of author information is available at the end of the article
Nitrobenzene is mostly used in the synthesis of aniline and in the production of benzidine, quinolone, and azobenzene [12]. Nitrobenzene is a pale yellow liquid, which has an almond-like odor at room temperature. The most common paths of occupational exposure to nitrobenzene are inhalation and absorption through the skin [12-15]. The reduction of nitrobenzene to aniline occurs once nitro
Data Loading...
