ABSTRACT
Cyanide is a chemical widely used in industry and is a major environmental pollutant and an important toxic asphyxiant, to which exposure occurs through inhalation as well as ingestion and skin contact. 1. This work aimed to measure the simple reaction time [SRT] in workers exposed to cyanide using our experimental modified reaction time ruler se which was approved by the Academy of The Scientific Research in 2002 and the reaction time standardized instrument 2. To confirm the efficacy of the ruler set by comparing its results with those of the standardized instrument. 3. To elicit the effect of smoking on cyanide level in blood. A cross-sectional study was carried out in a unit for hardening and metal plating process in 99-Army Factory, Helwan. One hundred male workers with a possibility of cyanide exposure were studied in addition to 100 male workers in the same factory without possible exposure to cyanide, as a control group. All exposed group were evaluated using a self-administered questiolmaire, medical examination and cognitive test including simple reaction time [ruler, instrument]. In addition, serum level of cyanide was measured for both groups and subgroups, comparing the results to the maximum serum level that might be present in normal non-exposed individuals. The mean age was 42.83 +/- 8.26 years and 41.45 +/- 8.1 years in the study and control groups, respectively. The mean duration of exposure to cyanide was 20.14 +/- 7.88 years. Environmental measurement of hydrogen cyanide [HCN] in air ranges between 9.2 and 9.3 ppm. The serum level of cyanide in the exposed workers who were also reported to be smokers was 0.08 +/- 0.01 1g/ml compared to 0.05 +/- 0.01 Ig/ml in smokers of the control group, a difference which is statistically significant. On the other hand, cyanide serum level in exposed, non-smoker workers was 0.05 +/- 0.01 compared to 0.0 1 +/- 0.01 jig/ml in non-smokers of the control group, a difference which is statistically significant. Simple reaction time ruler set assessment: statistical analysis showed mean and standard deviation of 31.04 and 4.02 for the exposed group and 21.46 and 1.16 for the control group. The difference is statistically significant [p < 0.001].Simple reaction time instrument assessment: Statistical analysis showed mean and standard deviation of 30.93 and 4.00 for the exposed group and 21.39 and 1.16 for the control group. The difference is statistically significant [p < 0.001]. Cyanide exposure causes lag of respofise as evidenced by prolongation of reaction time. We recommend using SRT ruler instead of instrument being cheep, simple and accurate with a short application time. Workers in industries with a hazard of cyanide exposure should wear protective mask, and work at a suitable spacing distance away from the source of cyanide release. Measuring SRT on periodic basis is recommended for early detection of cyanide poisoning in those workers