Analysis of crystalline phases in airborne particulate matter by two-dimensional X-ray diffraction (XRD2).

In this work, the potentiality of two-dimensional X-ray diffraction (XRD(2)) to characterise aerosol particles collected on commercial glass filters is presented. Indeed, even if routine analysis usually requires only mass determination, and rarely chemical composition, phase determination is fundamental to recognize the primary or secondary origin of the particulate matter and thus to determine the main sources of the pollution and to model contamination events. The experiments were performed at Daresbury Synchrotron (UK) Laboratory on 14.1 Beamline. The analysis of filters collected in Tuscany (Italy) is discussed with particular attention to the presence of arsenic sulfide. The first results of these experiments are very promising, showing the presence of unexpected compounds in the particulate matter of the investigated area.

[Interference of acetone in styrene metabolism in subjects exposed to both solvents]. / Interferenza dell'acetone sul metabolismo dello stirene in soggetti esposti ad entrambi i solventi.

Thirty-seven workers exposed to styrene and acetone in fiberglass industry were monitored on Monday and Thursday for 8 hours (two subsequent samplings of 4 hours each) using passive dosimeters (mod. TK200). The charcoal disks of the passive dosimeters were analysed by gas-chromatography. Urine samples were collected at the end of the workshift and before the start of the workshift the next morning (Tuesday and Friday). Mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured in the urine, using a HPLC method; values were expressed in mg/g of creatinine. The 8-h TWA exposure values ranged from 10 to 522 and 13 to 1581 mg/m3 on Monday and 8 to 423 and 10 to 579 mg/m3 on Thursday for styrene and acetone, respectively. Styrene TWA exposure values significantly correlated with the sum of metabolites at the end of workday (r = 0.72 on Monday and r = 0.91 on Thursday) and also the next morning (r = 0.88 on Tuesday and r = 0.85 on Friday). A calculated styrene exposure level of 213 mg/m3 (ACGIH-TLV) was associated with an excretion of metabolites (MA+PGA) higher on Thursday (814 mg/g creat.) than on Monday (600 mg/g creat.). The same observation was made on Friday (409 mg/g creat.) as compared with Tuesday (302 mg/g creat.). In conclusion, the TLV of styrene was associated with different values of metabolites at the beginning and at the end of the work-week. Moreover our data show that the simultaneous exposure to acetone does not modify the excretion of MA.

Blood styrene concentrations in a "normal" population and in exposed workers 16 hours after the end of the workshift.

Blood styrene was measured by a gas chromatography-mass spectrometry method in 81 "normal people" and in 76 workers exposed to styrene. In the normal subjects, styrene was also tested in alveolar and environmental air. Styrene was found in nearly all (95%) blood samples. Average styrene levels in the normal subjects were 221 ng/l in blood (Cb), 3 ng/l in alveolar air (Ca) and 6 ng/l in environmental air (Ci). Styrene levels did not differ significantly between smokers and nonsmokers, 95% of values being below 512 ng/l in Cb, 7 ng/l in Ca and 15 ng/l in Ci. In workers with an average exposure to styrene of 204 micrograms/l, at the end of the workshift, mean blood styrene concentration was 1211 micrograms/l. In blood samples collected at the end of the Thursday shift, styrene levels were significantly higher (1590 micrograms/l) than those found at the end of the Monday shift (1068 micrograms/l). A similar difference was found in samples taken the morning after exposure (60 and 119 micrograms/l, respectively). Significant correlations between blood and environmental styrene were found both at the end of the shift and the morning after exposure (r = 0.61 and 0.41, respectively). In workers occupationally exposed to styrene, 16 h after the end of the workshift, blood styrene (94 micrograms/l) was significantly higher than that found in the normal subjects (0.22 microgram/l). The half-life of blood styrene was 3.9 h.

Biological monitoring of workers exposed to styrene and acetone.

Twenty-two workers exposed to styrene and acetone in two fiberglass industries were monitored on Monday and Thursday for 8 hours using passive dosimeters. Urine samples were collected at the end of the workshift and before the start of the work on the next morning (Tuesday and Friday). The charcoal disks of the passive dosimeters were analysed by gas-chromatography. Mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured using a HPLC method; values were expressed in mg/g of creatinine. The 8-h TWA exposure values for styrene and acetone ranged respectively from 22 to 522 mg/m3 and 40-1581 mg/m3 on Monday; 25-423 mg/m3 and 55-579 mg/m3 on Thursday. Styrene TWA exposure values significantly correlate with the sum of metabolites at the end of workday (r = 0.70 on Monday and r = 0.95 on Thursday) and also at the next morning (r = 0.86 on Tuesday and r = 0.85 on Friday). A styrene exposure level of 213 mg/m3 (ACGIH-TLV) was associated with an excretion of metabolites (MA+PGA) higher on Thursday (803 mg/g creat) than on Monday (570 mg/g creat). The same result was found on Friday (459 mg/g creat) compared with Tuesday (305 mg/g creat). Moreover our data show that the simultaneous exposure to acetone does not modify the excretion of MA. In conclusion the TLV of styrene is associated with different values of metabolites at the beginning and at the end of the work-week.

[Oral symptoms in the climacteric. A prevalence study]. / Sintomi orali in climaterio. Studio di prevalenza.

The female climacteric is attributed to physiological ovarian failure with the consequent decrease in the secretions of oestrogen, progestones and androgens. Numerous metabolic, psychological and physical changes have been associated with this event. Oral discomfort, including the burning mouth syndrome and the dry mouth syndrome, has been described as a menopausal symptom. However, the relationship between the hormonal changes related to climacteric and the onset of oral discomfort is still controversial. The purpose of the present study was to evaluate the prevalence of oral symptoms, with particular regard to burning sensation, xerostomia, altered taste and recurrent oral ulcerations. The relationship between oral and climacteric symptoms and psychological status of the patients was also evaluated. A questionnaire was administered to 136 women (mean age: 51.2 years, range 40-62) being consecutively referred to the University Hospital Menopause Clinic from October 1991 to March 1992. The questionnaire included informations regarding menopausal state, oral symptoms, drug assumption, wearing of partial or total dentures, parafunctions (lip and cheek biting, bruxism, tongue thrusting). Climacteric symptoms including flushes/sweats, palpitations, headache, arthralgia/myalgia, vaginal dryness, decreased concentration, tiredness, decreased libido, insomnia, vertigo were evaluated. Visual analogue scale (VAS) was used where appropriate. Information regarding the alteration of the psychological status was collected by means of the Hospital Anxiety and Depression Scale Statistical analysis was performed by chi 2 test or Fisher's Exact Probability Test and Mann-Whitney U-test. The level of significance accepted was 5%. The subjects in this study were divided into two groups on the basis of their answers to the questionnaire: group I (no. 39), premenopausal women; group II (no. 97), menopausal women.(ABSTRACT TRUNCATED AT 250 WORDS)

[Prevalence of caries and malocclusion in Ferrara school children]. / Prevalenza di carie e malocclusioni in bambini in età scolare della provinica di Ferrara.

The Authors examined 459 children for caries and malocclusion in Argenta. 77% of the whole sample had caries and 65% of children had malocclusion. Dental health education and public preventive programs should be organized to prevent caries and malocclusion. An extension and improvement of local epidemiological studies are needed to achieve this purpose.

[Needles in dental practice. Clinical evaluation and experiments on deformation and siliconization]. / Gli aghi nella pratica odoontiatrica. Valutazione clinica e sperimentale relativa alla deformazione e siliconatura.

The authors have considered: a) the rate of the deformation of three different needles (Groups B, V, R) when used in different clinical conditions; b) the modification of the surface silicon of the needles after in vivo and in vitro stress. The results have shown a good behaviour of all the groups when employed through the mucous membrane, but a progressively increased deformation after contacts with an osseous surface, significantly higher for groups B and V than group R. No difference in the surface silicon, both among the groups and in relation to the technique of utilization.