Effect of simultaneous exposure to inhalational anesthetics and radiation on the adaptive response in operating room personnel

Some operating room personnel, such as orthopedic surgeons, are exposed simultaneously to inhalational anesthetics (IAs) and radiation that both can cause DNA damage. Some studies have shown that low doses of radiation reduce DNA damage when the cells are followed by a higher dose of the same or related agent. This study, therefore, set out to compare DNA damage in the anesthesiologists, radiologists, orthopedic surgeons, and healthcare staff (non-exposed group). In this cross-sectional study, breathing zone concentrations of anesthetic gas nitrous oxide (N₂O) were measured in the studied groups using standard method. Additionally, DNA damage was measured by micronucleus (MN) assay. The mean concentrations of N₂O in the anesthesiologists and orthopedic surgeons were 450.27 ± 327.44 ppm and 313.64 ± 216.14 ppm, respectively. The mean annual exposure to X-rays radiation in radiologists and orthopedic surgeons was 15.65 ± 8.46 mSy/year and 3.56 ± 1.32 mSy/year, respectively. MN frequencies were significantly higher in anesthesiologists and radiologists exposed to IAs and X-rays radiation respectively than in the non-exposed healthcare staff. While, there were no statistically significant differences between MN frequencies of orthopedic surgeons exposed to both IAs and radiation and healthcare staff. These findings suggest that an earlier exposure of orthopedic surgeons to a small dose of ionizing radiation can increase their resistance to genotoxicity caused by high doses of N₂O, a phenomenon that is called adaptive response.

The association between wood dust exposure and respiratory disorders and oxidative stress among furniture workers

BACKGROUND

This study was undertaken to determine the effect of wood dust on the respiratory system and oxidative stress in furniture workers and to determine whether any associations exist between respiratory parameters and oxidative stress.

METHODS

This cross-sectional study was performed on 45 furniture workers and 45 office workers as a reference group in Iran. The NIOSH method 0600 was used to determine the concentration of particulates. The prevalence of respiratory symptoms was estimated via the European Community Respiratory Health Survey (ECRHS) questionnaire. Oxidative stress biomarkers and respiratory parameters were also measured.

RESULTS

The mean concentrations of respirable and non-respirable dust were found to be 1.51 mg/m³ and 1.23 mg/m³, respectively. Pulmonary function parameters, including forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, and antioxidant capacity biomarkers such as total antioxidant capacity (TAC) and superoxide dismutase (SOD) were significantly lower, while the prevalence of respiratory symptoms, and malondialdehyde (MDA) levels, were significantly higher in the furniture workers than in the reference group. There were significant positive associations between FVC and FEV1 with SOD and TAC.

CONCLUSION

The present study results indicated that exposure to wood dust significantly increased respiratory disorders and confirmed the association between lung function parameters and oxidative stress.

Biochemical and hematological effects of lead exposure in Iranian battery workers

OBJECTIVE

The purpose of our study was to evaluate the hematotoxic, hepatotoxic, and nephrotoxic responses following lead exposure among battery workers.

MATERIAL AND METHODS

Seventy-eight battery workers exposed to lead, and 78 non-exposed subjects were studied. Fasting blood samples were collected to assess kidney and liver function and hematological parameters. To determine the breathing zone and blood lead levels (BLLs), the samples were analyzed in accordance with the 7082 and 8003 NIOSH methods, respectively.

RESULTS

The battery workers had significantly higher breathing zone lead and BLLs than the non-exposed group. In battery workers, the most hematological parameters, including red blood cell, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration, have significantly decreased. In contrast, white blood cell count has shown a significant increase as compared to the controls. The mean levels of alanine aminotransferase, aspartate aminotransferase as biomarker liver damage, and the serum levels of creatinine as a result of renal failure were significantly higher in the exposed group than in the non-exposed group.

CONCLUSIONS

These observations indicate that occupational exposure to lead exceeding its current threshold limit value (TLV) and biological exposure index (BEI) is associated with hematological symptoms and liver and kidney dysfunction.

Evaluation of total and differential white blood cell counts in workers exposed to lead

Introduction: Lead is a toxic heavy metal that has adverse health effects on blood parameters. About 80% of lead produced is used in batteries, especially vehicle batteries. Therefore, the present study aimed to assess the hematological changes, including total and differential white blood cell (WBC) counts in battery workers exposed to lead, and compare with the non-exposed group. Materials and Methods: This cross-sectional study was carried out in a battery industry in Semnan city. The study population consisted of 78 battery workers and 78 healthy non-exposed office workers. A hematology cell counter was used to determine the total, and differential WBC counts. Blood lead level was measured in accordance with the NIOSH method 8003. Results: Blood lead levels were about two times higher than the TLV recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) for this compound (20 µg/dl). The level of WBC (8.07± 2.55 mm3 blood×103 vs. 7.27 ± 1.58 mm3 blood×103) was significantly higher, while the level of monocyte was significantly lower (6.96 ± 1.72 % vs. 7.67 ± 1.87 %) in the exposed group than in the non-exposed group. After adjustment for potential confounders such as age and work history, a significant association between exposure to lead and WBC and monocyte levels was reported. Conclusion: The present study's findings indicated that exposure to lead was associated with total and differential white blood cells changes in the exposed group compared to the non-exposed group.

Association between genotoxic properties of inhalation anesthetics and oxidative stress biomarkers

Exposure to inhalation anesthetics (IAs) has been associated with DNA damage as reflected in the increased frequency of micronuclei (MN) and chromosomal aberrations (CAs). The present study was undertaken to ascertain whether there was any correlation between increased MN and CA and the extent of oxidative stress as well as the antioxidant status of a group of operating room personnel exposed to a mixture of IAs, including nitrous oxide, isoflurane, and sevoflurane. In this cross-sectional study, 60 operating room personnel (exposed group) in whom the frequencies of MN and CA had already been shown to be significantly higher than those of a referent group, as well as 60 unexposed nurses, were studied. Venous blood samples were taken from all participants, and malondialdehyde (MDA) levels as an index of oxidative stress (OS) and the activity of superoxide dismutase (SOD) and levels of total antioxidant capacity (TAC) as indices of antioxidant status were measured. The level of TAC (1.76 ± 0.59 mM vs. 2.13 ± 0.64 mM, p = 0.001) and the activity of SOD (11.22 ± 5.11 U/ml vs. 13.36 ± 4.12 U/ml, p = 0.01) were significantly lower, while the mean value of MDA was significantly higher (2.46 ± 0.66 µM vs. 2.19 ± 0.68 µM, p = 0.03) in the exposed group than in the nonexposed group. After adjusting for potential confounders, there were statistically significant associations between exposure to IAs, gender, SOD, and TAC with MN frequency and between exposure to IAs and SOD with numbers of CA. The findings of the present study indicated that exposure to IAs was associated with OS, and this, in turn, may be causally linked with DNA damage.

Genotoxic effect of exposure to polycyclic aromatic hydrocarbons (PAHs) in asphalt workers

Asphalt workers are at risk due to exposure to asphalt fumes containing polycyclic aromatic hydrocarbons (PAHs). The main purpose of this study was to measure the urinary metabolite of PAHs and to determine its effect on micronucleus (MN) formation as an indicator of genotoxic damage. In this cross-sectional study, the MN frequency in 48 male asphalt workers exposed to PAHs was measured and compared with 48 male non-exposed employees. PAHs exposure was evaluated by determining urinary 1-Hydroxypyrene (1-OHP). The mean concentrations of 1-OHP in the exposed and non-exposed groups were 0.58 ± 0.41 μmol/mol creatinine and 0.38 ± 0.25 μmol/mol creatinine, respectively. 1-OHP concentration was significantly higher in smokers compared with non-smokers in both exposed and non-exposed groups. Moreover, the mean MN frequency in the exposed group was significantly higher than in the non-exposed group. The MN frequency was significantly higher in asphalt workers with a work history of ≥ 15 years compared to workers with lower work history. In a fully adjusted model, there was a statistically significant association between exposure to PAHs, with MN and 1-OHP concentration, and between smoking status with 1-OHP. The findings of the present study indicated that occupational exposure to PAHs was associated with increased urinary 1-OHP as well as DNA damage in the asphalt workers.