Monitoring of cyanobacterial blooms and assessing polymer-enhanced microfiltration and ultrafiltration for microcystin removal in an Italian drinking water treatment plant.

The water intake of a drinking water treatment plant (DWTP) in Central Italy was monitored over six bloom seasons for cyanotoxin severity, which supplies drinking water from an oligo-mesotrophic lake with microcystin levels up to 10.3 µg/L. The historical data showed that the water temperature did not show extreme/large seasonal variation and it was not correlated either with cyanobacterial growth or microcystin concentration. Among all parameters, the cyanobacteria growth was negatively correlated with humidity and manganese and positively correlated with atmospheric temperature. No significant correlation was found between microcystin concentration and the climatic parameters. Polymer(chitosan)-enhanced microfiltration (PEMF) and ultrafiltration (PEUF) were further tested as an alternative microcystin removal approach from dense cyanobacteria-rich flows. The dominant cyanobacteria in the water intake, Planktothrix rubescens, was isolated and enriched to simulate cyanobacterial blooms in the lake. The PEMF and PEUF were separately applied to enriched P. rubescens culture (PC) (microcystin = 1.236 µg/L) as well as to the sand filter backwash water (SFBW) of the DWTP where microcystin concentration was higher than 12 µg/L. The overall microcystin removal rates from the final effluent of PC (always <0.15 µg/L) were between 90.1-94.7% and 89.5-95.4% using 4 and 20 mg chitosan/L, respectively. Meanwhile, after the PEMF and PEUF of SFBW, the final effluent contained only 0.099 and 0.057 µg microcystin/L with an overall removal >99%. The presented results are the first from the application of chitosan to remove P. rubescens as well as the implementation of PEMF and PEUF on SFBW to remove cyanobacterial cells and associated toxins.

A cohort mortality study of leather tanners in Tuscany, Italy.

BACKGROUND: Work in leather tanning may involve exposure to a wide range of chemicals. Some of these are carcinogens or suspected carcinogens. Increased risk for a number of cancers have been reported, although there are considerable inconsistencies between studies. The present study investigates the mortality of leather tanners in Tuscany, Italy. METHODS: Tanneries were selected from the 1996 Valdarno Inferiore Tanneries Census and were in operation since December 31, 1970. Employees were followed until December 31, 1998 through company records, and the National and Regional Death Index. Demographic and work history data were abstracted from company payrolls. Regional mortality rates were used to calculate Standardized Mortality Ratio (SMR). Analyses were completed for the overall cohort (men and women) and for men who ever worked as of finisher, chrome tanners, and vegetable tanner (only men). RESULTS: The cohort consisted of 4,874 workers (4,150 males and 724 females) employed in 92 tanneries active in 1996 and operating on December 31, 1970. Ascertainment of vital status and cause of death were completed for all individuals by the end of follow-up, December 31, 1998. Males showed increases for cancer of the endocrine glands (SMR 5.67, 4 observed (obs), 90% Confidence Intervals (CI) 195-1,308), blood diseases (SMR 3.29, 4 obs, 90% CI 112-753), mental disorders (SMR 1.95, 6 obs, 90% CI 85-385), violence and accidents (SMR 1.30, 54 obs, 90% CI 102-163). Mortality from myeloid leukemia was increased in males (SMR 2.08, 5 obs, 90% CI 82-437) and in females (SMR 5.99, 2 obs, 90% CI 106-1,887). One death from nasal cancer was observed versus 0.2 expected. Mortality from lung cancer was increased among finishers (SMR 1.45, 19 obs, 90% CI 95-212), an increase was observed also for bladder cancer (SMR 1.25, 2 obs, 90% CI 22-393) and pancreatic cancer (SMR 1.20, 2 obs, 90% CI 21-379). CONCLUSIONS: The study confirms previous observations among tanners of increased mortality from lung, bladder, and pancreatic cancer. Noteworthy are the increased mortality from myeloid leukemia together with the new findings of an increased mortality from endocrine glands tumors, blood diseases, and psychiatric disorders which should be considered with caution because of the small number of cases and the novelty of the observation.

[A series of cases of sinonasal cancer among shoemakers and tannery workers]. / Analisi di una serie di casi di neoplasie maligne delle fosse nasali e dei seni accessori nel settore conciario e delle calzature.

A series of cases of sinunasal cancer has been observed among shoe-makers (11 cases) and tannery workers (8 cases) in the leather production area in Tuscany in the period 1990-2002. We stress the possible etiologic role of tannins both in leather and in wood industry.