[Intellectual quotient and environmental exposure to low doses of lead]. / Quoziente intellettivo ed esposizione ambientale a basse dosi di piombo.

The effects of low-level lead exposure on children's intelligence quotient (IQ) were investigated in 64 Sardinian adolescents (13-16 years old). To estimate potential early adverse effects on the Central Nervous System (CNS) due to very low-level lead, the Intelligence Quotient (IQ) of adolescents with present blood lead concentrations (PbB) generally below 10 microg/dl was measured. We analyzed blood lead concentration and individual IQ of 32 Sardinian children living in Portoscuso, a town 2 Km far from a lead smelter, and of other 32 controls living in S. Antioco, a town about 15 Km far from the same smelter. The Wechsler Intelligence Scale for Children Revised (WISC-R) was administered. The relation between IQ and blood lead concentration was estimated by linear multivariate models adjusting for several potential confounders, such as the educational and socio-economic level of the parents. The blood lead concentration was in average significantly higher in the Portoscuso group compared to controls. The linear model applied to the total population studied (n 64) showed that the blood lead concentration was inversely and significantly associated with IQ, with an extrapolated decline of 1.29 points in total IQ for each microg/dl increase of lead blood concentration. According to the recent scientific literature on this topic, results of our pilot study suggest the need to further lower the blood lead concentration for children to a threshold significantly below 10 microg/dl, value till now considered "safe" for the children's CNS.

[Study on mortality by specific cause among workers at a lead and zinc foundry in Sardinia]. / Studio di mortalità per cause specifiche in lavoratori di una fonderia di piombo e zinco della Sardegna.

The mortality of 918 Sardinian lead-smelter workers followed between 1972 and 2001 is reported. The assessment of individual exposure to inorganic lead was based on several environmental and blood lead measurements available, for each department and task, between 1985 and 2001. The mortality for all cancers was within the expected numbers (SMR 1.01, n 108). Even if not statistically significant, the mortality for gastric cancer (SMR 1.22, n 4), for lung cancer (SMR 1.21, n 18) and for lymphomas and leukaemias (SMR 1.82, n 6) was higher than that expected from the regional rates during the follow-up. Only for the lung cancer mortality a statistically significant upward trend with increasing categories of lead exposure was observed (SMR 1.96, 95% CI 1.02-3.68 for the highest exposure group). Our study, even if of small size, suggests an association between occupational exposure to inorganic lead and lung cancer risk.

[Cognitive and performance capacity among adolescents living near a lead and zinc smelter]. / Capacità cognitive e di performance in adolescenti residenti in prossimità di una fonderia di piombo e zinco.

To estimate potential early adverse effects on the Central Nervous System (CNS) due to very low exposure to inorganic lead, the Intelligence Quotient (IQ) of adolescents with present blood lead concentrations (PhB) generally below 10 micrograms/dl was measured. We analyzed blood lead concentration and individual IQ of 32 Sardinian adolescents living in Portoscuso, a town 2 Km far from a lead smelter, and of other 32 controls living in S. Antioco, a town about 15 Km far from the same smelter. The Wechsler Intelligence Scale for Children Revised (WISC-R) was administered. The relation between IQ and blood lead concentration was estimated by linear multivariate models adjusting for several potential confounders, such as the educational and socio-economic level of the parents. The blood lead concentration was in average significantly higher in the Portoscuso group compared to controls. The linear model applied to the total population studied (n 64) showed that the blood lead concentration was inversely and significantly associated with IQ, with an extrapolated decline of 1.29 points in total IQ for each microgram/dl increase of blood concentration. According to the recent scientific literature on this topic, results of our pilot study suggest the need to further lower the definition of an elevated blood lead concentration for children to a threshold significantly below 10 micrograms/dl, value till now considered "safe" for the children's CNS.

[Mortality from lung cancer among workers of a Sardinian lead smelter [Follow-up: 1972-2001]]. / Mortalità per cancro polmonare in lavoratori di una fonderia di piombo della Sardegna [Follow-up: 1972-2001].

The mortality of 918 Sardinian lead-smelter workers followed between 1972 and 2001 is reported. The assessment of individual exposure to inorganic lead was based on several environmental and blood lead measurements available, for each department and task, between 1985 and 2001. The mortality for all cancers was within the expected numbers (SMR 1.01, n 108). Even if not statistically significant, the mortality for gastric cancer (SMR 1.22, n 4), for lung cancer (SMR 1.21, n 18) and for lymphomas and leukaemias (SMR 1.82, n 6) was higher than that expected from the regional rates during the follow-up. Only for the lung cancer mortality a statistically significant upward trend with increasing categories of lead exposure was observed (SMR 1.96, 95% CI 1.02-3.68 for the highest exposure group). Our study, even if of small size, suggests an association between occupational exposure to inorganic lead and lung cancer risk.

[Shift-work and cardiovascular diseases among chemical industry workers]. / Lavoro a turni e patologia cardiovascolare in operai di un'industria chimica.

In order to assess the prevalence of cardiovascular abnormalities among shift workers, who were free from such abnormalities at the time of hiring, compared to day workers and ex-shift workers, we studied the QTc interval and several cardiovascular risk factors in 61 chemical workers, including 40 shift workers, 11 day workers, and 10 ex-shift workers. We found a high prevalence rate of ischemic heart disease and conduction abnormalities among ex-shift workers (5/10, 50%). We did not observe variations in the QTc interval among the three groups. The occurrence of cardiovascular disease is a reason for moving workers to day work. Therefore, the shift workers group in our study might have been selected among subjects with a healthier lifestyle preventing side effects on their cardiovascular system.

Neurotoxic effect of lead at low concentrations.

The effects of lead exposure at low concentrations were evaluated by studying the post-rotatory nystagmus (PRN) in two groups of rats exposed for 3 months to 50 parts per million (ppm) of sodium acetate and 50 ppm of lead acetate, respectively, in the drinking water. Only animals treated with lead acetate showed changes of the PRN parameters which were significantly related to the concentration of lead in the blood and in brain structures. The patterns of PRN responses were characterized and classified into four types: progressively inhibitory (40%), prematurely inhibitory (25%), late inhibitory (25%), and excitatory-inhibitory (10%). No alterations of the PRN parameters were observed in the animals treated with sodium acetate. The results show that exposure to lead, even at low concentrations, impairs both sensory and motor functions. The findings also point out that the vestibular system and brain stem structures which generate and control the PRN represent targets of the action of this heavy metal. Finally, the results indicate that the evaluation of the vestibulo-ocular-reflex can provide a test suited for the screening of the neurotoxic effects of lead even in the absence of clinical signs typical of lead intoxication.

[The energy cost and the use of individual protective devices in firefighters]. / Costo energetico e uso di D.P.I. nei vigili del fuoco.

Firefighters are required to wear fire-protection devices when involved in hazardous work situations. To determine whether fire protective clothing and self-contained breathing apparatus (SCBA) affect maximal physical work performance and to assess their additional energy requirement, we studied a cohort of Italian firemen while performing a rapid air-stair climbing (Mt. 29). Heart rate (HR) and maximal speed (time/distance) were measured in 23 firemen during the exercises, performed either wearing fire protection clothing and SCBA (p2) and service dress (p1). We also measured maximal oxygen consumption (VO2 max, indirect determination), WBGT and the speed/HR ratio (iR) as an arbitrary index of physical work performance. The participant reached the sub-maximal HR in both exercises (p1 87.01%; p2 88.84%). Fire protection devices significantly reduced the exercise maximal speed (p < 0.001) and increased the maximal HR (p < 0.01). IR index was significantly (p < 0.001) lower for p2, indicating a reduction of physical work performance (-26.9%); VO2 max was inversely related with mean and maximal HR (p < 0.001). These results suggest that only well trained firefighters should be employed in emergency actions requiring fire protection devices and SCBA.

[Methods of evaluating results of physical rehabilitation]. / A propos des méthodes d'évaluation des résultats du réentraînement physique.

Besides simple techniques of control of a readaptation program, the authors stress the importance of quantifying the intensity of the efforts imposed. They propose the comparative study of different parameters measured precisely at the level of well tolerated submaximal work: VE/VO2, SaO2/VO2 which they analize together with the effort test standardized by the EEC.

[Determination of the pneumoconiosis hazard in the cork industry]. / Accertamento del rischio pneumoconiogeno nell'industria del sughero.

The AA. have carried out an epidemiological investigation in order to control the prevalence of chronic respiratory diseases on a group of 385 people working in several cork industries in North Sardinia. At the same time an environmental investigation has been carried out. Standard questionnaire (CECA questionnaire) for chronic bronchitis and pulmonary emphysema, standard chest X-ray film, spyrographic investigation, ECG and sputum analysis for acid resistent bacteria have been used for epidemiological investigation. Environmental dust concentration and individual dust exposure, environmental concentration of sulphur oxides, nitrogen oxides, carbon mono- and dioxide, ammonia nad microclimatic conditions have been studied. Examination of medical data shows only a low degree of respiratory pathology in contrast with results of other authors, probably because of different methods used for epidemiological investigation and data interpretation and because of different environmental and working conditions.