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Biomedical subjects

L Piacitelli

Publications and source records attributed to L Piacitelli.

8 recordsLinked to original sources
PubMed2001

Risk assessment for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) based on an epidemiologic study.

The International Agency for Research on Cancer (Lyon, France) recently concluded that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a human carcinogen. There have been few human studies and risk assessments with quantitative exposure data. The authors previously conducted exposure-response analyses based on estimated external TCDD exposure for 3,538 US male chemical workers and found a positive trend for all cancer with increasing cumulative exposure. In the present study, 1988 data from 170 workers with both estimated external exposure and known serum TCDD levels were used to derive the relation between the two. This derived relation was used to estimate serum TCDD levels over time for all 3,538 workers, and new dose-response analyses were conducted by using cumulative serum level. A positive trend (p = 0.003) was found between estimated log cumulative TCDD serum level and cancer mortality. For males, the excess lifetime (75 years) risk of dying of cancer given a TCDD intake of 1.0 pg/kg of body weight per day, twice the background intake, was an estimated 0.05-0.9% above a background lifetime risk of cancer death of 12.4%. Data from this cohort are consistent with another epidemiologic risk assessment from Germany and support recent conclusions by the US Environmental Protection Agency.

Cohort Studies↗
PubMed2000

A retrospective job exposure matrix for estimating exposure to 2,3,7, 8-tetrachlorodibenzo-p-dioxin.

BACKGROUND: A job exposure matrix was developed to estimate the 2,3, 7,8-tetrachlorodibenzo-p-dioxin exposure of 3,538 workers who produced 2,4,5-trichlorophenol and its derivatives. METHODS: Daily TCDD exposure scores that were plant, process, and period specific were estimated for each job title as the product of 1) the concentration of TCDD (microg/g); 2) a qualitative factor to account for the extent of worker contact and 3) time exposed to TCDD contamination. Daily scores were summed to compute individual cumulative TCDD exposure scores. RESULTS: Daily TCDD exposure scores ranged from 0.001 to 1,250. Cumulative TCDD scores ranged from 0.002 to 1,559,430. The 393 workers with records of chloracne in the TCDD exposure cohort (11%) had markedly higher cumulative scores than those with no record of chloracne (a median score of 11,546 vs. 77). CONCLUSIONS: The cumulative TCDD exposure scores incorporate both duration and level of exposure, and permit the relative ranking of worker exposures for the evaluation of exposure-response relationships between TCDD exposure and mortality in an updated cohort study analysis.

Algorithms↗
PubMed1999

Cancer, heart disease, and diabetes in workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

BACKGROUND: In 1997, the International Agency for Research on Cancer classified 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as a group 1 human carcinogen, based largely on four highly exposed industrial cohorts that showed an excess of all cancers combined. In this study, we extended the follow-up period for the largest of these cohorts by 6 years and developed a job-exposure matrix. METHODS: We did cohort mortality analyses involving 5132 chemical workers at 12 U.S. plants by use of life table techniques (U.S. population referent) and Cox regression (internal referent). We conducted exposure-response analyses for 69% of the cohort with adequate work history data and adequate plant data on TCDD contamination. All P values are two-sided. RESULTS: The standardized mortality ratio (SMR) for all cancers combined was 1.13 (95% confidence interval = 1.02-1.25). We found statistically significant positive linear trends in SMRs with increasing exposure for all cancers combined and for lung cancer. The SMR for all cancers combined for the highest exposure group was 1.60 (95% confidence interval = 1.15-1.82). SMRs for heart disease showed a weak increasing trend with higher exposure (P = .14). Diabetes (any mention on the death certificate) showed a negative exposure-response trend. Internal analyses with Cox regression found statistically significant trends for cancer (15-year lag time) and heart disease (no lag). CONCLUSIONS: Our analyses suggest that high TCDD exposure results in an excess of all cancers combined, without any marked specificity. However, excess cancer was limited to the highest exposed workers, with exposures that were likely to have been 100-1000 times higher than those experienced by the general population and similar to the TCDD levels used in animal studies.

Carcinogens↗
PubMed1983

Pneumoconiosis and lung function in a group of kaolin workers.

In June 1981, 65 current and former workers at a kaolin mine and mill were examined by chest radiography, spirometry, and a questionnaire. Five (13%) of 39 current workers and 3 (19%) of 16 former workers with 5 yr or more of exposure had radiographic evidence of pneumoconiosis. Among the 8 workers with pneumoconiosis, conglomerate upper lobe lesions were present in one half. No pneumoconiosis was observed among 8 current workers with less than 5 yr of exposure. Lung function testing showed significant reductions (p less than 0.05) in FVC, FEV1, and peak flow rate in kaolin workers compared with that in a control group. Environmental sampling during the testing period showed airborne dust to be composed of kaolinite (96%) and titanium dioxide (4%). Additional controlled epidemiologic studies among kaolin workers are needed to generate reliable prevalence data for pneumoconiosis and to assess the impact of dust exposure on pulmonary function.

Adult↗
PubMed1983

Kaolin and the lung.

Explore the source record for details and available documents.

Environmental Exposure↗
PubMed1982

Mutagenicity of oil-shale ash.

3 oil-shale ash samples were extracted with solvents and analyzed for mutagenicity with a number of tests systems. In Salmonella typhimurium, the ash extracts were highly mutagenic with the Ames his reversion and the ara-resistant systems. Mutation induction by the ash in Salmonella was independent of metabolic activation and was of the frameshift type. These ash extracts showed a substantial killing effect, but failed to induced ad-3 reversion in Neurospora crassa, gene conversion and mitotic crossing-over in Saccharomyces cerevisiae and TGr mutation in cultured CHO cells.

Animals↗
PubMedDate not supplied

Serum levels of polychlorinated dibenzo-p-dioxins and dibenzofurans in pulp and paper mill workers.

Serum levels of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) among 46 long-term workers at a pulp and paper mill were compared to the levels in 16 community residents who never worked at the mill. Overall, there were no appreciable differences among the three exposure groups (community resident, low-exposure-potential worker, high-exposure-potential worker) for specific PCDDs or PCDFs. Neither exposure group nor duration in high-exposure-potential-jobs was related to total toxic equivalents (I-TEQ). Serum levels of PCDDs and PCDFs in this study generally were within the range previously reported for persons with no known occupational exposure.

Adult↗