scholarly journals Practical learnings from an epidemiology study on TDI-related occupational asthma: Part II—Exposure without respiratory protection to TWA-8 values indicative of peak events is a good indicator of risk

2020 ◽  
Vol 36 (11) ◽  
pp. 885-891
Author(s):  
Patrick M Plehiers ◽  
Anne H Chappelle ◽  
Mark W Spence
Keyword(s):  
Occupational Asthma ◽  
Situational Awareness ◽  
Weighted Average ◽  
Toluene Diisocyanate ◽  
Cumulative Exposure ◽  
Respiratory Protection ◽  
Epidemiology Study ◽  
Direct Reading ◽  
Asthma Incidence ◽  
Anonymized Data

The anonymized data of an epidemiology study on the incidence of toluene diisocyanate (TDI)-related occupational asthma in three US-based TDI production facilities have been reanalyzed to identify where to best focus exposure reduction efforts in industrial practice in order to reduce the risk of sensitization to TDI. In Part I, it was demonstrated that cumulative exposure is not a good indicator of the risk of developing TDI-related occupational asthma. In this Part II, an alternative model was developed based on net exposure parameters (i.e. samples taken when no respiratory protection was used). A statistically significant relationship was determined between asthma incidence and the frequency of exposure to TDI levels indicative of peak events that are expressed as time-weighted average-8 (TWA-8) values greater than 3 ppb during which no respiratory protection was used. This relationship suggests a threshold to induction of TDI-related asthma. The findings also highlight the importance of a comprehensive program for controlling workplace atmosphere in the plant by technical measures (e.g. selection of equipment, cleaning procedures) and controlling exposure by organizational measures and situational awareness (e.g. training, use of in-the-field direct reading indicators) during high potential exposure scenarios (e.g. line breaking, spills) to encourage or enforce the appropriate use of respiratory protection.

scholarly journals Practical learnings from an epidemiology study on TDI-related occupational asthma: Part I—Cumulative exposure is not a good indicator of risk

2020 ◽  
Vol 36 (11) ◽  
pp. 876-884 ◽  
Author(s):  
Patrick M Plehiers ◽  
Anne H Chappelle ◽  
Mark W Spence
Keyword(s):  
Occupational Asthma ◽  
Weighted Average ◽  
Toluene Diisocyanate ◽  
Cumulative Exposure ◽  
Respiratory Protection ◽  
Epidemiology Study ◽  
Average Value ◽  
Asthma Incidence ◽  
Anonymized Data ◽  
Epidemiology Studies

The anonymized data of an epidemiology study on incidence of toluene diisocyanate (TDI)-related occupational asthma in three US-based TDI production facilities have been reanalyzed to identify where to best focus exposure reduction efforts in industrial practice to reduce the risk of sensitization to TDI. Since the induction of sensitization has sometimes been attributed to cumulative exposure, this relationship was examined first. Gross cumulative exposure values (i.e. not taking into account whether respiratory protection was used or not) and net cumulative exposure values (i.e. accounting for the use of respiratory protection) per participant were calculated based on the duration of their study participation and the average time-weighted average value of the exposure group to which they belonged. These two sets of cumulative exposure data were compared with asthma incidence using logistic regression. Incidence was zero among workers who rarely come into contact with open plant systems (e.g. during maintenance or spills). Notwithstanding, no statistically significant relationship between asthma incidence and either gross or net cumulative exposure could be determined. This is shown to be consistent with the results of several other epidemiology studies on TDI-related occupational asthma. In conclusion, cumulative exposure values are not a good indicator of the risk of developing TDI-related occupational asthma.

Increased oxidative stress and plasma Hsp70 levels among gasoline filling station attendants

2016 ◽  
Vol 33 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Bing Xia ◽  
Kangcheng Chen ◽  
Yingnan Lv ◽  
Damin Huang ◽  
Jing Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stress Protein ◽  
Weighted Average ◽  
Exposed Group ◽  
Cumulative Exposure ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Gasoline Station ◽  
Filling Station ◽  
Exposed Workers

Objectives: Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn) and is used as an antiknock agent and octane enhancer in gasoline. In this article, we tested the oxidative stress and heat stress protein (Hsp) 70 levels of gasoline station attendants to explore potential plasma biomarkers. Furthermore, the dose–response relationship was also identified. Methods: A total of 144 workers, including 96 petrol fillers and 48 cashiers, participated in the study. Ambient concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) and Mn were monitored at nine filling stations. During the measuring process, the individual cumulative exposure index was calculated. Plasma oxidative stress and Hsp70 levels were also analysed using enzyme-linked immunosorbent assay. Results: The BTEX time-weighted average in office areas was significantly lower than in refuelling areas ( p < 0.05). In refuelling areas, the content of Mn ranged from 6.44 μg/m3 to 127.34 μg/m3, which was much higher than that in office areas (3.16–7.22 μg/m3; p < 0.05). Exposed workers had significantly different plasma oxidative stress indicators compared with the control group, respectively: superoxide dismutase (SOD), 39.18 ± 6.05 U/mL versus 52.84 ± 3.87 U/mL; glutathione peroxidase (GSH-Px), 186.07 ± 15.63 U versus 194.38 ± 10.42 U; and malondialdehyde (MDA), 1.68 ± 0.52 nmol/L versus 1.43 ± 0.64 nmol/L (in all comparisons, p < 0.05). Plasma Hsp70 level in the exposed group (2.77 ± 0.64 ng/mL) was significantly higher than in the control group (2.32 ± 0.87 ng/mL; p < 0.05). Furthermore, Hsp70 levels were inversely correlated with the activities of SOD ( r = −0.305) and GSH-Px ( r = −0.302) in the exposed group ( p < 0.05). Moreover, a positive correlation ( r = 0.653) was found between plasma Hsp70 levels and plasma MDA levels ( p < 0.05). Conclusion: Exposure to MMT-containing gasoline may result in increasing reactive oxygen stress among filling station attendants. Plasma Hsp70 levels could be used as a sensitive responsive biomarker for exposed workers.

Serum ferritin and transferrin levels are not serologic markers of toluene diisocyanate–induced occupational asthma

2010 ◽  
Vol 125 (3) ◽  
pp. 762-764 ◽  
Author(s):  
Joaquín Sastre ◽  
Beatriz Sastre ◽  
Mar Fernández-Nieto ◽  
Ignacio Pérez-Camo ◽  
José Javier Sánchez ◽  
...  
Keyword(s):  
Serum Ferritin ◽  
Occupational Asthma ◽  
Toluene Diisocyanate ◽  
Serologic Markers

The HLA DRB1*1501-DQB1*0602-DPB1*0501 Haplotype Is a Risk Factor for Toluene Diisocyanate-Induced Occupational Asthma

2009 ◽  
Vol 150 (2) ◽  
pp. 156-163 ◽  
Author(s):  
Jeong-Hee Choi ◽  
Kyung-Wha Lee ◽  
Cheol-Woo Kim ◽  
Choon-Sik Park ◽  
Hyun-Young Lee ◽  
...  
Keyword(s):  
Risk Factor ◽  
Occupational Asthma ◽  
Toluene Diisocyanate

scholarly journals Benzene Exposure and Biomarkers in Alveolar Air and Urine Among Deck Crews on Tankers Transporting Gasoline

2019 ◽  
Vol 63 (8) ◽  
pp. 890-897 ◽  
Author(s):  
Karl Forsell ◽  
Ingrid Liljelind ◽  
Göran Ljungkvist ◽  
Rolf Nordlinder ◽  
Eva Andersson ◽  
...  
Keyword(s):  
Weighted Average ◽  
Occupational Exposures ◽  
Exposure Level ◽  
Respiratory Protection ◽  
Muconic Acid ◽  
Alveolar Air ◽  
Benzene Exposure ◽  
Exposure Limit ◽  
Level Of Significance ◽  
Post Shift

Abstract Introduction Increased rates of leukaemia have been found among tanker crews. Occupational exposures to the leukomogen benzene during loading, unloading, and tank cleaning are possible causes. Studies on older types of tankers carrying gasoline with most handling being done manually have revealed important exposures to benzene. Our study explores benzene exposures on tankers with both automatic and manual systems. Correlations between benzene exposure and benzene in alveolar air (AlvBe), benzene in urine (UBe), and trans,trans-muconic acid (ttMA) in urine were investigated. Methods Forty-three male seafarers (22 deck crewmembers and 21 not on deck) on five Swedish different product and chemical tankers transporting 95- or 98-octane gasoline were investigated between 1995 and 1998. The tankers used closed systems for the loading and unloading of gasoline but stripping and tank cleaning were done manually. Benzene in respiratory air was measured using personal passive dosimeters during a 4-h work shift. Samples for biomarker analyses were collected pre- and post-shift. Smoking did occur and crewmembers did not use any respiratory protection during work. Results The average 4-h benzene exposure level for exposed was 0.45 mg m−3 and for non-exposed 0.02 mg m−3. Benzene exposure varied with type of work (range 0.02–143 mg m−3). AlvBe, UBe, and ttMA were significantly higher in post-shift samples among exposed and correlated with exposure level (r = 0.89, 0.74, and 0.57, respectively). Smoking did not change the level of significance among exposed. Discussion Benzene in alveolar air, unmetabolized benzene, and ttMA in urine are potential biomarkers for occupational benzene exposure. Biomarkers were detectable in non-exposed, suggesting benzene exposure even for other work categories on board tankers. Work on tankers carrying gasoline with more or less closed handling of the cargo may still lead to significant benzene exposure for deck crewmembers, and even exceed the Swedish Occupational Exposure Limit (OEL; 8-h time-weighted average [TWA]) of 1.5 mg m−3.

scholarly journals A Cohort Study on Respiratory Symptoms and Diseases Caused by Toner-Handling Work: Longitudinal Analyses from 2003 to 2013

Atmosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 647
Author(s):  
Niina Terunuma ◽  
Kazunori Ikegami ◽  
Hiroko Kitamura ◽  
Hajime Ando ◽  
Shizuka Kurosaki ◽  
...  
Keyword(s):  
Cohort Study ◽  
Respiratory Disease ◽  
Respiratory Symptoms ◽  
Weighted Average ◽  
Baseline Survey ◽  
Control Group ◽  
Respiratory Protection ◽  
Exposure Group ◽  
High Concentration ◽  
Time Weighted Average

The purpose of this study was to examine the effects of toner-handling work on respiratory symptoms and diseases. We conducted a prospective cohort study of 1468 workers between 2003 and 2013. The cohort included 887 toner-handling workers and 581 non-toner-handling workers, employed in one toner and copier manufacturing enterprise. Toner-handling workers were subdivided into two groups based on the 8-h time-weighted average toner exposure concentration for each work category in the baseline survey. We compared the incidence of respiratory disease and longitudinal changes in the prevalence of subjective respiratory symptoms among three groups, as follows: High-concentration toner exposure group, the low-concentration toner exposure group, and a control group. The incidence of respiratory disease and changes in the prevalence of subjective respiratory symptoms were similar between the non-toner-handling group and the toner-handling group. In contrast, the odds ratio for yearly changes in the prevalence of wheezing without asthmatic response was significantly lower in the high-concentration toner exposure group than in the control group. At the study site, dust scattering was well controlled and workers used respiratory protection appropriately. These findings suggest that toner-handling work had little adverse effect on respiratory function in a work environment with sufficiently controlled ventilation.

scholarly journals Medical Monitoring for Occupational Asthma Among Toluene Diisocyanate Production Workers in the United States

2017 ◽  
Vol 59 ◽  
pp. S13-S21 ◽  
Author(s):  
Laura D. Cassidy ◽  
Brent Doney ◽  
Mei Lin Wang ◽  
Laura Kurth ◽  
Patrick R. Conner ◽  
...  
Keyword(s):  
United States ◽  
Occupational Asthma ◽  
The United States ◽  
Toluene Diisocyanate ◽  
Medical Monitoring
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