Route exposure and adverse effects monitoring of Aflatoxin B1 in the workers of wet waste management, the role of body redox system modulation.

Exposure to dust, containing different fungi metabolites such as aflatoxins is a risk factor for developing liver and kidney health abnormalities. Occupational evaluation of the aflatoxin's exposure-induced health abnormalities should include the monitoring of bioaerosols in the workplace and personal air, and applying of appropriate blood biomarkers to assess Aflatoxin B1 (AFB1) detrimental effects on a worker's health. However, to the best of our knowledge, these appropriate methods, especially determining the associated-adverse effects on health, following exposure, haven't been well documented in the literature at the wet waste handling sites. In the current study, the AFB1 quantity in the area, personal, and settled dust in wet household waste handling samples and AFB1-Albumin levels in the serum of workers in comparison with the control group were determined using high-pressure liquid chromatography with a fluorescent detector (HPLC-FLD) methods. Moreover, the adverse effects of AFB1 on the liver and kidney biochemical profiles of the exposed workers and its relation to antioxidant capacity in the household wet waste sorting were recorded in a consolidated investigation. The results demonstrated that the average airborne dust concentration and its associated AFB1 content were significantly higher in wet waste management sections as compared to the control place, corresponding to the serum AFB1-Albumin levels of workers. Furthermore, AFB1-induced changes in the serum biochemicals evaluating liver and kidney function tests and antioxidant profiles of workers in wet waste handling sections were indicative of their function abnormalities. The results imply AFB1-induced adverse effects on the liver and kidney functions may be mediated through the body redox system modulation.

Liver and kidney serum profile abnormalities in workers exposed to aflatoxin B1 in urban solid waste management centers.

Many workers are exposed to health problems arising from molds, fungi, and their toxins during waste processing. Aflatoxin B1 (AFB1) level in airborne and settled dust, aflatoxin B1-albumin (AFB1-Alb) adduct in serum, liver and kidney biochemical tests, and body redox change of workers in municipal dry waste-processing sites were investigated. The surface, personal, and area air dust and the blood of workers' samples were collected from the plastic and bread waste-sorting sections in three recycling municipal dry waste sites. Digestion (only for serum samples), passed through SPE cartridge, elution, and collection with methanol, immune-affinity column clean-up, and HPLC system equipped with post-column derivatization method and fluorescence detection were performed for determination of AFB1 and AFB1-Alb levels in the samples. The mean level of dust and AFB1 in the personal and area air, and in the settled dust and the AFB1-Alb in the serum of workers in the bread waste sorting, was higher than plastic waste-sorting samples, in all of the sites. The differences in the biochemical profiles of subjects exposed to aflatoxin B1 as compared to the control group especially in liver and kidney function parameters as well as antioxidant factors of the serum were significant. The workers in handling of municipal waste may be exposed to potentially hazardous levels of aflatoxin B1. The adverse effects of AFB1 on the kidney and liver may be caused by changes in the redox system.

Factors affecting unsafe behavior in construction projects: development and validation of a new questionnaire.

Introduction. Occupational safety in general, and construction safety in particular, is a complex phenomenon. This study was designed to develop a new valid measure to evaluate factors affecting unsafe behavior in the construction industry. Methods. A new questionnaire was generated from qualitative research according to the principles of grounded theory. Key measurement properties (face validity, content validity, construct validity, reliability and discriminative validity) were examined using qualitative and quantitative approaches. The receiver operating characteristic curve was used to estimate the discriminating power and the optimal cutoff score. Results. Construct validity revealed an interpretable 12-factor structure which explained 61.87% of variance. Good internal consistency (Cronbach's α = 0.94) and stability (intra-class correlation coefficient = 0.93) were found for the new instrument. The area under the curve, sensitivity and specificity were 0.80, 0.80 and 0.75, respectively. The new instrument also discriminated safety performance among the construction sites with different workers' accident histories (F = 6.40, p < 0.05). Conclusion. The new instrument appears to be a valid, reliable and sensitive instrument that will contribute to investigating the root causes of workers' unsafe behaviors, thus promoting safety performance in the construction industry.

A qualitative investigation of factors influencing unsafe work behaviors on construction projects.

BACKGROUND: Unsafe behavior is an important component in the chain of accident occurrences, and thus plays a key role in the accident prevention programs in construction sites. OBJECTIVE: The aim of this qualitative research is to study the perception of frontline workers, supervisors, and managers about the preconditions of and contributing factors to unsafe behaviors in civil engineering projects. METHODS: Field observation, in-depth interview, and focus group discussion are conducted with 113 informants from various mega projects during a 2-year time period. Fishbone diagram is applied to describe a conceptual model. RESULTS: The results point to fourteen themes within four categories of the conceptual model - general management, organizational factors, safety supervision and management, and individual characteristics. CONCLUSIONS: General management and organizational culture were introduced as important preconditions and contributing factors resulting in human error and unsafe behavior in the construction sites. The fishbone diagram reveals the sequence and interaction of preconditions and contributing factors. The key contributing factors and their influences on unsafe behaviors are discussed along with recommendations for future directions.

Factors influencing unsafe behaviors and accidents on construction sites: a review.

OBJECTIVE: Construction is a hazardous occupation due to the unique nature of activities involved and the repetitiveness of several field behaviors. The aim of this methodological and theoretical review is to explore the empirical factors influencing unsafe behaviors and accidents on construction sites. METHODS: In this work, results and findings from 56 related previous studies were investigated. These studies were categorized based on their design, type, methods of data collection, analytical methods, variables, and key findings. A qualitative content analysis procedure was used to extract variables, themes, and factors. In addition, all studies were reviewed to determine the quality rating and to evaluate the strength of provided evidence. RESULTS: The content analysis identified 8 main categories: (a) society, (b) organization, (c) project management, (d) supervision, (e) contractor, (f) site condition, (g) work group, and (h) individual characteristics. The review highlighted the importance of more distal factors, e.g., society and organization, and project management, that may contribute to reducing the likelihood of unsafe behaviors and accidents through the promotion of site condition and individual features (as proximal factors). CONCLUSION: Further research is necessary to provide a better understanding of the links between unsafe behavior theories and empirical findings, challenge theoretical assumptions, develop new applied theories, and make stronger recommendations.

Modeling the factors affecting unsafe behavior in the construction industry from safety supervisors' perspective.

BACKGROUND: There can be little doubt that the construction is the most hazardous industry in the worldwide. This study was designed to modeling the factors affecting unsafe behavior from the perspective of safety supervisors. METHODS: The qualitative research was conducted to extract a conceptual model. A structural model was then developed based on a questionnaire survey (n=266) by two stage Structural Equation Model (SEM) approach. RESULTS: An excellent confirmed 12-factors structure explained about 62% of variances unsafe behavior in the construction industry. A good fit structural model indicated that safety climate factors were positively correlated with safety individual factors (P<0.001) and workplace safety condition (P<0.001). The workplace safety condition was found to play a strong mediating role in linking the safety climate and construction workers' engagement in safe or unsafe behavior. CONCLUSIONS: In order to improve construction safety performance, more focus on the workplace condition is required.

Structural modeling of safety performance in construction industry.

BACKGROUND: With rapid economic development and industrialization, the construction industry continues to rank among the most hazardous industries in the world. Therefore, construction safety is always a significant concern for both practitioners and researchers. The objective of this study was to create a structural modeling of components that influence the safety performance in construction projects. METHODS: We followed a two-stage Structural Equation Model based on a questionnaire study (n=230). In the first stage, we applied the Structural Equation Model to the proposed model to test the validity of the observed variables of each latent variable. In the next stage, we modified the proposed model. The LISREL 8.8 software was used to conduct the analysis of the structural model. RESULTS: A good-fit structural model (Goodness of Fit Index=0.92; Root Mean Square Residual=0.04; Root Mean Square Error of Approximation=0.04; Comparative Fit Index=0.98; Normalized Fit Index=0.96) indicated that social and organizational constructs influence safety performance via the general component of the safety climate. CONCLUSION: The new structural model can be used to provide better understanding of the links between safety performance indicators and contributing components, and make stronger recommendations for effective intervention in construction projects.

Adverse effects of formaldehyde vapor on mouse sperm parameters and testicular tissue.

BACKGROUND: Formaldehyde (FA), one of the simplest organic molecules, is a flammable, pungent, irritating and colorless gas. This study aimed to investigate the effects of various concentrations of FA vapor on sperm parameters and testicular tissue. MATERIALS AND METHODS: In this experimental study, we randomly assigned 36 adult male mice to one control and two experimental groups (n=12 for each group). The control group (C) did not receive FA. Group F1 (low concentration) was exposed to 10 ppm FA vapor and the F2 (high concentration) group was exposed to 20 ppm FA vapor. FA was administered for ten days, eight hours per day for both groups. At the end of the exposure period, half of the animals in each group were sacrificed 24 hours after exposure to detect any short-term effects; the rest of the mice were sacrificed 35 days later to assess for long-term effects. Sperm parameters were analyzed by Computer-assisted Sperm Analyzer (CASA) and histological changes determined. In addition, we studied changes in testosterone hormone. Data were analyzed by one-way ANOVA followed by the Scheffe test using SPSS software. RESULTS: Long-term effects of FA in the experimental groups included significant reductions in sperm cell numbers and sperm viability. A drastic reduction in progressive motility and increased abnormal sperm percentage (p<0.001) compared with the control group was also noted. Histological study of testes specimens in the experimental group revealed displacement of germinal cells, along with degeneration of Leydig cells and seminiferous tubules. CONCLUSION: Exposure to FA vapor can destroy testicular structure and decrease percentages of concentration, viability, normal morphology, and progressive motility, in addition to increasing the percentage of immotile sperm.