Evaluation of exposure to noise in seafarers on several types of vessels in Polish Merchant Navy.

Noise was measured on merchant ships of 3 types, during routine sea voyages. It was found that the equivalent noise levels calculated for engine crew members exceeded the accepted hygienic norm by 1-2 dB. Also audiometric examinations at the beginning and on completion of a voyage were performed, enrolling seamen from the engine room and from the deck crews. They showed statistically significant differences of temporary shift of the hearing threshold, more pronounced in the engine room crew.

Exposure of the crew of a fishing trawler-factory ship to noise.

The noise level was measured in the workplaces and in living quarters on a fishing trawler-factory ship, type B-418, in the fishing grounds. It was found, that an average noise level in the engine room was from 97 to 104 dB A. The noise level registered in the living and resting areas on board did not exceed the admissible values. In the fish processing plant the noise levels ranged from 84 to 97 dB A. The equivalent noise level for the engine room crew exceeded 90 dB A by 7-15 dB A; in the fish processing plant and on the bridge it remained within the norm limits.

Evaluation of the exposure of a merchant ship crew to mechanical vibration during a sea voyage.

Vibration levels were measured on a Roll-on/Roll-off type ship, during her voyage, with the use of Bruel and Kjaer equipment. The calculated equivalent values of mechanical vibration accelerations for various workplaces and for living quarters did not exceed the acceptable levels, according to Polish hygienic standards for border values of comfort of work. The intensity of vibration in selected places was generally determined by longitudinal vibration. The prevailing frequency was 8 Hz.

Right atrial temperature and electrical activity during cardioplegic cardiac arrest.

In 18 patients undergoing coronary artery bypass surgery the relation between right atrial temperature and right atrial electrical reactivation during cardioplegic cardiac arrest was studied. The administration of cardioplegic solution induced immediate ventricular and atrial arrest in all patients. No recurrence of ventricular activity was observed while right atrial activity subsequently recurred in 11 patients. Activity at the surface ECG was recorded only in one patient with right atrial reactivation. No right atrial electrical activity was found below 19 degrees C. The average atrial temperature was 21.5 degrees C while the average apex temperature was 15 degrees C. The study has confirmed previous observations that during cardioplegic cardiac arrest the right atrium is not as well protected as the ventricular tissue against rewarming. Monitoring of the right atrial electrical activity or right atrial temperature is essential to ensure atrial arrest during the entire period of cardioplegic cardiac arrest.

Supraventricular tachyarrhythmias after coronary bypass surgery--a double blind randomized trial of prophylactic low dose propranolol.

In the present study 75 patients were double blind randomized either to receive 10 mg propranolol orally 4 times a day (35 patients) or a placebo (40 patients). Episodes of clinically important supraventricular tachyarrhythmias were recorded in the first 4 postoperative days. They appeared in 5 of 35 patients receiving propranolol and in 5 of 40 patients receiving placebo (no statistically significant difference). In conclusion this study indicates the need for further evaluation to clarify if low-dose propranolol or any other drug is effective in reducing the frequency of SVT in the early postoperative period after coronary artery bypass surgery.

Pseudoaneurysm of the left ventricle as a complication of septic embolism.

A case report of pseudoaneurysm (PA) of the left ventricle due to acute myocardial infarction (AMI) caused by septic embolism from the infected aortic valve is presented. The patient was operated upon with resection of the left ventricular wall and insertion of a bioprosthesis in the aortic ostium. Because of reoccurrence of PA 4 weeks postoperatively due to a pinhole defect in the left ventricular wall near the suture-line, reoperation was performed. The patient was discharged home and at follow-up, 6 months postoperatively, his cardiologic condition had improved.

The noise and functional disturbances of the cardio-vascular system in seamen.

The work presents quantitative relations between service-dependent noise dose levels and "unspecific" for the noise influence remote effects basing on the study of the cardiovascular system of 207 members of the deck and engine room crews. The seamen observed had no hearing losses due to noise (according to the ISO standard 1999). The study carried out in the pause between sea-going voyages showed that when the length of the service exceeded 10 years the noise dose increment of 1 dB corresponds to the hypertension frequency increment of 2%. The increase of the dose and the length of the service turns out as a trend towards the diminished mean arterial pulse pressure (AP) and elevated diastolic and mean dynamic AP. By resorting to the correlation-regression analysis the information value of the mean dynamic AP for the noise influence evaluation was shown as well the possibility to determine the safe noise action dose which may not be over 100 dB at the service length under 40 years.

[Effectiveness of ear protective devices]. / Skutecznosc tlumienia nausznikowych ochron sluchu.

Efficiency of 9 types of hearing protectors was investigated. A subjective method of an absolute hearing threshold shift in free sound field in 20 well-hearing-persons was applied. The results obtained are presented in figures. It was found that the maximum efficiency of most hearing protectors usually fell toon the frequency of 4000 Hz and amounted to 20--41 dB. The minimum efficiency usually fell to the frequency of 125 Hz and amounted to 8--21 dB. Attenuation efficiency of broad-band noise was 18-40 dB and approximated the maximum efficiency of pure sounds, sometimes even surpassing it. The results of determinations differed from the values given by manufacturers, which accounts for the need of undertaking such investigations.