How does airway exposure of aflatoxin B1 affect serum albumin adduct concentrations? Evidence based on epidemiological study and animal experimentation

Abstract

-Aflatoxin B1 (AFB1) airway inhalation represents an additional route of exposure to this toxin. However, the association between AFB1 inhalation and serum AFB1 albumin adducts remains unclear. The aim of this study was to explore the association between airway exposure to AFB1 and serum AFB1 albumin adduct concentrations via an epidemiological study, as well as in an AFB1 airway exposure animal model. Our epidemiological study was conducted in a sugar factory in the Guangxi Autonomous Region of China. In order to examine fungal contamination, air samples were obtained in the workshop and areas outside the workshop, such as the office and nearby store. Dust samples were also collected from the bagasse warehouse and presser workshop, and were analyzed using an indirect competitive enzyme-linked immunosorbent assay (ELISA). Additionally, blood samples were collected from a total of 121 workshop workers, and a control group (n = 80) was comprised of workers who undertook administrative tasks or other work outside the workshop. The animal experiment was conducted in the laboratory animal center of Guangxi Medical University, where a total of 60 adult male rabbits were involved in this study. By intubation, AFB1 was administered in three groups of rabbits daily, at dose rates of 0.075, 0.05 and 0.025 mg/kg/day for a period of 7 days. Blood samples were collected on day 1, day 3, day 7 and day 21, and the measurements of the AFB1 albumin adducts in the serum were performed by a double antibody sandwich ELISA. The epidemiological study showed that serum albumin adducts were detected in 67 workshop workers (55.37%), and the values ranged 6.4 pg/mg albumin to 212 pg/mg albumin (mean value: 51 ± 4.62 pg/mg albumin). In contrast, serum albumin adducts were detected in only 7 control group participants, with the values ranging from 9 pg AFB1/mg albumin to 59 pg/mg albumin (mean value: 20 ± 13.72 pg/mg albumin). The animal experiment revealed that the rabbits had detectable levels of AFB1 in their serum with a minimum effective dose of 0.05 mg/kg/day; while 11 of 17 (64.71%) rabbits had detectable levels of AFB1 albumin adducts in the high exposure group (0.075 mg/kg/day), and only 5 rabbits (26.32%) had detectable levels of AFB1 albumin adducts in the moderate exposure group (0.05 mg/kg/day). No rabbits had detectable levels of AFB1 albumin adducts in the low exposure group (0.025 mg/kg/day). Our results demonstrated that only exposure to a certain level of AFB1 would result in detectable levels of serum AFB1 albumin adducts. Interventional programs aimed at reducing exposure to AFB1 by inhalation are urgently needed in high-risk populations. Additional large-sample, well-designed randomized controlled trials are needed to further confirm our results.

Occupational Exposure to Aflatoxin B1 in a Portuguese Poultry Slaughterhouse

“…However, and contrary to previous published articles (Viegas et al, 2012c(Viegas et al, , 2013a(Viegas et al, , b, 2015Mo et al, 2014) we cannot state that exposure is occurring only by inhalation since the workers enrolled in this study are from different workplaces conditions in the same slaughterhouse. Regarding the specific case of evisceration workplace, where eight workers obtained results higher than the LOD, and since there is a low particle contamination in the air (data published elsewhere), exposure can be occurring by dermal absorption contrary to other situations already reported in different settings (Viegas et al, 2013a(Viegas et al, , b, 2015Mayer et al, 2012).…”

“…The main objective was to obtain data regarding recent exposure to AFB1 and also its level of intensity. This approach is useful for rapid screening for acute exposures and also reflects chronic exposure (Viegas et al, 2012c(Viegas et al, , 2013a(Viegas et al, , b, 2015Leong et al, 2012;Mo et al, 2014).…”

Occupational Exposure to Mycotoxins—Different Sampling Strategies Telling a Common Story Regarding Occupational Studies Performed in Portugal (2012–2020)

“…However, in the same study, mycotoxins were not detected in air samples collected in the same facilities (active sampling methods) [49]. Thus, the use of passive sampling methods such as settled dust appears to be the best option for mycotoxins assessment in occupational environments [18,50,51]. Interestingly, settled dust did not show any fungal growth supporting the evidence that the indoor presence of fungal species does not imply the exposure to mycotoxins and vice versa.…”

Exposure to airborne mycotoxins: the riskiest working environments and tasks

“… Lai et al (2014) observed an elevated risk of hepatocellular carcinoma (HCC) for sugar and papermaking workers with airway exposure to Aspergillus flavus-contaminated dust respect to controls. In similar working environments, low-dose exposure to AFB1 was associated with lung cancer while heavy and prolonged exposure to airway AFB1 may be complicated by the development of lung cancer and HCC ( Mo et al 2014 ).…”