Bilateral hearing loss after dichloromethane poisoning: a case report

Effects of dichloromethane, nitrate, and sulfhemoglobin-induced substances on carboxyhemoglobin detection: a comprehensive review

Carbon monoxide (CO) is a common gaseous toxin that causes severe poisoning symptoms. Accurate detection of the formation of carboxyhemoglobin (COHb) in the blood is very important for the identification of CO poisoning. In this review, the effects of exogenous toxins, including dichloromethane (DCM), nitrite, and hydrogen sulfide, on the determination of COHb by spectrophotometry are summarized by comparing epidemiological data, case studies, and analytical methods. The mechanism of the effects of these exogenous poisons on COHb detection is described, and the extent of their influence on the clinical diagnosis and forensic identification of CO poisoning is discussed. We suggest that emergency medicine and forensic science practices need to improve the understanding of these toxins and optimize clinical diagnosis and evaluation strategies to address the effects of toxins on the determination of COHb.

The Characteristics, Sources, and Health Risks of Volatile Organic Compounds in an Industrial Area of Nanjing

This study investigates the chemical complexity and toxicity of volatile organic compounds (VOCs) emitted from national petrochemical industrial parks and their effects on air quality in an industrial area of Nanjing, China. Field measurements were conducted from 1 December 2022, to 17 April 2023, focusing on VOC concentrations and speciations, diurnal variations, ozone formation potential (OFP), source identification, and associated health risks. The results revealed an average total VOC (TVOC) concentration of 15.9 ± 12.9 ppb and an average OFP of 90.1 ± 109.5 μg m-3. Alkanes constituted the largest fraction of VOCs, accounting for 44.1%, while alkenes emerged as the primary contributors to OFP, comprising 52.8%. TVOC concentrations peaked before dawn, a pattern attributed to early morning industrial activities and nighttime heavy vehicle operations. During periods classified as clean, when ozone levels were below 160 μg m-3, both TVOC (15.9 ± 12.9 ppb) and OFP (90.4 ± 110.0 μg m-3) concentrations were higher than those during polluted hours. The analysis identified the key sources of VOC emissions, including automobile exhaust, oil and gas evaporation, and industrial discharges, with additional potential pollution sources identified in adjacent regions. Health risk assessments indicated that acrolein exceeded the non-carcinogenic risk threshold at specific times. Moreover, trichloromethane, 1,3-butadiene, 1,2-dichloroethane, and benzene were found to surpass the acceptable lifetime carcinogenic risk level (1 × 10-6) during certain periods. These findings highlight the urgent need for enhanced monitoring and regulatory measures aimed at mitigating VOC emissions and protecting public health in industrial areas. In the context of complex air pollution in urban industrial areas, policymakers should focus on controlling industrial and vehicle emissions, which can not only reduce secondary pollution, but also inhibit the harm of toxic substances on human health.

Sudden hearing loss following acute carbon monoxide poisoning: A case report and literature review

Introduction:

Acute carbon monoxide (CO) poisoning could lead to headache, dizziness, myocardial injury, neurological sequela, and death. Sudden hearing loss is a rare symptom of acute CO poisoning.

Case Presentation:

Here, we report a case of a 42-year-old woman who suffered from acute hearing loss after exposure to a suicidal environment of high concentration of CO. Partial recovery of hearing was demonstrated after a combination of corticosteroid and hyperbaric oxygen therapy was given.

Discussion:

The mechanism of sudden hearing loss caused by acute CO poisoning is not well-established. It is believed to be related with the hypoxic damage to the cochlea. The characteristic of sudden hearing loss caused by acute CO poisoning is that it often affects in high frequency bilaterally.

Conclusion:

This report would prompt the clinician in early recognition of this sudden hearing loss of uncommon etiology.

Cochlear dysfunction is associated with styrene exposure in humans

AIM

Occupational exposure to styrene has been shown to be associated with an increased probability of developing hearing loss. However, the sites of lesions in the auditory system in humans remain unknown. The aim of this study was to investigate the possible adverse effects of styrene exposure on the cochlea of human subjects.

DESIGN

The hearing function of 98 styrene-exposed male workers from the glass fibre-reinforced plastics industry (mean concentration of 55 mg/m3) was evaluated bilaterally using pure-tone audiometry (1000-16000 Hz), distortion product otoacoustic emissions (DPOAEs), and auditory brainstem response (ABR). The results were compared to a group of 111 male workers exposed to noise (above 85 dBA) and 70 male white-collar workers exposed to neither noise nor solvents. Age and noise exposure levels were accounted for as confounding variables in all statistical models.

RESULTS

Styrene exposure was significantly associated with poorer pure-tone thresholds (1-8 kHz), lower DPOAE amplitudes (5-6 kHz), and shorter wave V latencies in both ears compared to control-group subjects. Similar results were found among noise-exposed subjects. A further analysis with wave V latency showed that styrene-exposed subjects showed significantly shorter latencies than expected according to normative data. These results suggest that occupational exposure to styrene at moderate concentrations is associated with cochlear dysfunction, at least at high frequencies. DPOAEs may be considered a valuable diagnostic tool in hearing conservation programs in workers exposed to styrene.

Accidental poisoning by intramuscular injection of dichloromethane and trichloroethylene: A case report

Introduction:

Dichloromethane (DCM) and trichloroethylene (TCE) are both common halohydrocarbons which are widely used in industry. The most common exposure route of DCM or TCE is inhalation, but intramuscular injection of DCM and TCE is very rarely.

Case presentation:

A 47-year-old male presented ecchymosis, pain, and swelling of the left limb following accident injection of ABS glue (main ingredients were DCM and TCE). The swelling of his left limb was lasted until day 6 and WBC, NEUT, CK, CK-MB, LDH, AST and ALT were elevated until day 9. He was received intravenous fluids, analgesic, antibiotics, and other supportive measures and finally discharged from the hospital on day 16.

Discussion:

Both DCM and TCE could cause local irritation and systemic toxicity involving central nervous system, liver, kidney and other organs. In this case, because the small dose of toxicant and injection being the route of exposure, the patient mainly suffered from local toxicity resulting in painful soft tissue swelling with slight hemocytology and biochemistry disorder. Although there are no specific antidotes for DCM and TCE poisoning, supportive measures may also provide satisfactory therapeutic results.

Conclusions:

DCM and TCE poisoning following intramuscular injection could present mainly with local and system poisoning symptoms and successfully treated with supportive measures.

IgA nephropathy in a laboratory worker that progressed to end-stage renal disease: a case report

Background

IgA nephropathy (IgAN) is the most common form of glomerulonephritis, a principal cause of end-stage renal disease (ESRD) worldwide. The mechanisms of onset and progression of IgAN have not been fully revealed, and epidemiologic studies have yielded diverging opinions as to the role of occupational exposure to organic solvents in the initiation or worsening of IgAN. As the authors encountered a laboratory worker with IgAN that progressed to ESRD, we present a case report of IgAN progression due to dichloromethane exposure along with a review of literature.

Case presentation

A 41-year-old male laboratory worker began to experience gross painless hematuria after two years of occupational exposure to toluene. Although clinical follow-up was initiated under the impression of IgAN based on clinical findings, the patient continued to work for four more years in the same laboratory, during which he was in charge of laboratory analysis with direct exposure to a high concentration of dichloromethane without proper protective equipment. During that time, his renal function rapidly worsened and finally progressed to ESRD 10 years after the first clinical symptoms. The result of exposure assessment through reenactment of his work exceeded the occupational exposure limit for dichloromethane to a considerable degree.

Conclusions

The causal association between occupational solvent exposure and IgAN is still unclear; therefore, this case report could be used as a basis to support the relevance of occupational solvent exposure to IgAN and/or its progression. Early intervention as well as close monitoring of laboratory workers exposed to various organic solvents is important to prevent or delay the progression of glomerulonephritis to ESRD in the occupational setting.