G Ital Med Lav Erg 2002; 24:1, 43-48 © PI-ME, Pavia 2002 www.gimle.fsm.it C. Abbate, C. Giorgianni, F. Munaò 1 , C. Costa, R. Brecciaroli, M. Barbaro Effects of noise on functional cardiovascular parameters: a follow-up study Department of Social and Territorial Medicine, University of Messina 1 Chair of Medical Statistics, University of Messina Introduction The relations between noise and effects on cardiova- scular apparatus have been studied for long by numerous authors, but often leading to different conclusions. Some authors (1, 4, 6, 13, 18, 28) tend to deny a signi- ficant relation between arterial blood pressure and noise, whereas others (2, 5, 10, 24, 27, 36, 40) have reported an increase both in systolic and diastolic blood pressure (SBP and DBP respectively) in exposed populations. The conclusions of different authors as regards heart rate (HR) are not less discordant. Spinazzola et al. (30) and Van Dijk et al. (37), in their reviews, report that various authors attribute to noise a significant increase in HR; on the other hand, Fogari et al. (10), in their cohort studies, consider not significant the variations in the HR attributed to acute exposure to noise; similarly, Amato et al. (1) and others attribute to the pollutant no effect on this parameter. Aim of this study is to search, by means of a follow-up design, into the relations between noise and cardiovascular effects. Method The sample was selected from a population of 8,263 employees with different qualifications in the oil chemical area (refining, distribution of fuel and clerk), working for 5 different firms and thus undergoing periodical clinical examination. A homogeneous sample was selected retro- spectively, and the widest comparable group resulted to be the one consisting of workers employed in this field at the age of 23 years. Therefore, given the wide size of the initial population, our analysis focused only on this group in order to start with a homogeneous sample. The first selection criteria adopted were male sex and - in order to simplify the statistical analysis - having been engaged by the firm at the age of 23. The population initially involved in the study consisted of 1340 subjects. The following exclusion criteria were then adopted to select the sample, collecting information from clinical hi- story and sanitary cards: RIASSUNTO. Lo scopo del presente studio è quello di fornire un contributo alle conoscenze sulle relazioni, a tutt’oggi controverse, tra esposizione al rumore e funzione cardiovascolare. Si tratta di un follow up eseguito su una popolazione di 757 lavoratori di sesso maschile impiegati in cinque diversi impianti industriali del ramo petrolchimico. I lavoratori selezionati sulla base dell’esposizione al rumore, sono stati suddivisi in tre gruppi omogenei a) impiegati (non esposti), b) autisti (esposizione compresa tra 80-85 dBA) c) operai (esposizione superiore a 85 dBA). La popolazione è stata indagata attraverso la misurazione della FC e della PA con cadenza trimestrale per una durata di 12 anni. Ogni sessione di misure era rappresentato da tre rilevazioni settimanali. Dall’analisi dei dati emerge che tutti i parametri osservati tendono ad un progressivo incremento correlato con età ed anzianità lavorativa. Il confronto tra i singoli parametri evidenzia che 1. la FC non risulta influenzata dall’esposizione al rumore; 2. la PA risulta invece significativamente differente tra esposti e controlli; 3. la PAD risulta il parametro più sensibile all’esposizione al rumore, riuscendo a differenziare anche i campioni di esposti. In conclusione dai dati dello studio risulta che l’esposizione al rumore influenza la pressione arteriosa, in particolar modo la diastolica, mentre non sembra avere influenza sulla FC. Parole chiave: rumore, pressione sanguigna, frequenza cardiaca. ABSTRACT. www.gimle.fsm.it - The aim of this follow-up design study is to give a contribution to the knowledge of the controversial relations between noise and functional cardiovascular parameters. The study population consisted of 757 male employees working for 5 different firms in the oil chemical area (refining and distribution of fuel) with different qualifications - 345 workers, 212 drivers, 200 clerks - and thus exposed to 3 different levels of noise (85-90 dBA, 80-85 dBA and <80 dBA respectively). Heart rate, systolic and diastolic blood pressure were monitored 3 days a week at the beginning of the working shift, for a period of 12 years. The analysis of the data obtained indicates that all the 3 parameters under observation tend to increase progressively with the age and working age of the subjects. In the comparison between the 3 levels of exposure, heart rate results not affected by the exposure to noise; systolic blood pressure results sensitive only for the discrimination of the effects due to exposure, showing a statistically significant difference only between clerks on one side and workers and drivers on the other; diastolic blood pressure is highly influenced by the level of exposure to noise, showing significantly different slopes for the 3 groups. In conclusion, blood pressure is a parameter definitely more reliable for the correlation to the level of exposure, while heart rate cannot be considered a marker of exposure to noise. Key words: noise, blood pressure, heart rate.