We used a Monte Carlo MC approach to generate the large number of simulated samples of BPb and to understand the most likely BPb value in each job category. We considered the potential sources of variability and uncertainty in the BPb distributions as a probability density function based on measured values. Thus, hazard occurrence probability can be calculated by using the proportion of simulated HI which value is greater than 1.
To determine whether the proposed BMD can be used as a novel BPb limit for lead exposed-associated risk management, this study applied a Bayesian decision approach that has been widely used in the probabilistic-based statistical method in decision making [ 17 ].
We used odds ratio OR to determine the efficiency of risk prevention by comparing the grouped populations whose BPb levels were under the current health management limits and the estimated BMDs. The OR was estimated as,.
Finally, hazard prevention probability was calculated by using the proportion of simulated ORs. Statistics and regressions of this study were conducted in the open source language R Version 3. The Cochran-Armitage test for trend analysis was used to assess the presence of a dose-response relationship. To integrate the risk estimates across different models, the model-averaging BMD was applied by calculating the weight w k.
Uncertainty is a key factor in risk assessment that can influence the precision of risk estimation [ 21 ]. This study considered the uncertainty and its impact on the expected risk estimates that were quantified by MC simulation.
Each simulation was carried out with 10, iterations to assure the stability of its probability distribution. Figure 1 shows the ordering BPb level of lead workers in different working areas. Male workers in the lead battery manufacturing processes of grinding, cutting, and filling had relatively higher BPb concentrations than those in other working areas. Median BPb concentrations were estimated The highest BPb concentration was observed in lead stearate factories. Compared with male workers, female workers in lead battery factories had lower BPb levels.
The distributions of the abnormal number in hematological indicators are shown in Table 2. Overall, the abnormal proportions ranged between 0 and To investigate the association of specific hematological indicators with BPbs, we performed a Pearson-based correlation analysis Fig.
The model averaging BMD 10 estimates were Among female workers, model averaging BMD 10 estimates were 8. We found that the highest hazard occurrence probability was in male grinding workers with median HI of 1. The overall risk in HI for lead-exposed workers was 0. Risk contribution analysis indicated that female workers in the assembling group contributed a significant high risk to the total population, with a contribution proportion of Female workers are represented by light gray.
Based on the probability distribution Fig. Figure 5 shows the results of decision analysis. Confounding was addressed using data stratification. ORs and adjusted ORs in male workers were 1.
ORs and adjusted ORs were 1. The estimated ORs and adjusted ORs, respectively, were 0. The hazard prevention probabilities were estimated This study focuses on lead exposure-related anemia risk. Therefore, we used hematological indicators to represent BPb-induced anemia.
The Hct, Hgb, and RBC were representative indicators of lead-associated occupational anemia and can be used to evaluate the critical BPb levels to protect lead workers [ 16 ]. In addition to common indicators, our study also applied the measurements of MCV, MCH, and MCHC, which were calculated by three original indicators to estimate the possible critical values. This study found that BPb-related hematological effects of anemia were consistent with previous studies [ 16 , 22 ].
Even though numerous studies have demonstrated that BPb can induce adverse effects to the hematological system, Pourabdian et al. Some confounders such as menstruation, smoking, and working status may influence the relationships between BPb and hematological indicators.
In this study, the BMD model gave us an opportunity to estimate the critical effect dose for BPb-associated anemia in workers. BMD modeling has been utilized as a more precise mathematical approach for performing toxicological risk assessment [ 24 ]. Overall, the BMD models provide more accurate and precise value by using the computational approach, which considers the uncertainty from the epidemiological information and mathematical models.
Our estimation of BMD 10 was similar to those reported by Karita et al. According to the recent statement from American College of Occupational and Environmental Medicine ACOEM , BPb is still a reliable and wide-used biomonitoring indicator for the health effects associated with lead exposure. The most notable effect is the increased cardiovascular risks at these BPb levels, but the adverse pregnancy outcomes and other effects may also occur.
Risk assessment results demonstrated that lead workers are likely to work in unsafe workplaces. Unacceptable hazard occurrence probability was approximately Female workers in the assembling group had a higher risk of Risk contribution was However, the highest hazard contribution in male lead workers was estimated at only 9.
It seems that appropriate engineering control measures and hygiene strategies still play an important role in limiting lead exposure for female lead workers [ 27 ]. To determine whether the estimated critical values of BPb can be used as the novel limit for health management, this study successfully applied a Bayesian analysis approach integrated with MC simulation to estimate the uncertainty and reliability of risk control efficiency.
Our approach had also been widely used in exposure analysis and risk decision-making in environmental and occupational health research [ 28 , 29 ]. Our results found out that there were slight differences when considering these two BPb levels for male workers. Therefore, the suitable BPb level of male workers for health management of anemia can be set in this interval. The BPb-hematological BMDs for female workers were lower than male, indicating that female workers are more vulnerable for lead-related anemia than male.
The hazard prevention probabilities for female workers were Thus, the anemia risk can also be reduced when a more stringent BPb level is adopted. Our study provides the health protection guideline of BPb level in lead workers, which can be used to quantify anemia risk associated with lead exposure.
This study did not focus on the exposure assessment of airborne lead. Compared with environmental monitoring of airborne lead concentration and permissible exposure level, BPb is more reliable and can be used to determine gender-specific health effects of lead. In addition, the airborne lead cannot fully reflect the health risk if the company successfully implements personal protection equipment and industrial hygiene.
This study could not investigate and control the other possible sources of lead exposure outside the work and get the complete information on previous experience of lead-related work. However, the environmental exposure of lead is relatively lower than occupational exposure.
This study focuses on the dose-response relationship between BPb concentration and the hematological indicators from regular health examination. The BPb was mainly sourced from the current workplace. Therefore, we assumed that the cumulative BPb that sourced from workplace or other area can be associated with the change of the hematological indicators. Flora et al. By contrast, our study found that BPb-related hematological effects may display gender-specificity due to inter-individual variability.
Furthemore, there is no evidence of a safe exposure level for renal and cardiac effects associated with exposure to lead [ 31 , 32 ]. According to our correlation analysis, we found that BPb had significantly negative correlations with hematological indicators in male workers.
However, this correlation was not observed in female workers. This result might due to the fact that female workers had relatively lower BPb levels compared to males. Moreover, we were unable to collect information about the menstruation or pregnancy from our collated data for female workers.
This data gap may influence our risk estimation results. The constructed dose-response relationship was an atypical S-shape in our effect analysis.
We observed some abnormal hematological indicators in female workers who had lower BPb concentrations, an effect which may have been due to menstruation or pregnancy. Nonetheless, BPb levels in female workers needs to be carefully revised in order to prevent the lead-related anemia risk.
In addition to hematological effects of anemia, health effects of low-dose lead also include hypertension, cognitive dysfunction, renal, and reproductive effects. Lead may also be genotoxic [ 33 , 34 ]. Neuropsychological effects of lead toxicity were also determined to be a common occupational hazard of lead toxicity [ 35 ]. Ahmad et al. Therefore, lead workers might suffer from illnesses associated with low-level lead exposure.
Computational approaches are a useful research tool in the health risk assessment of chemical exposure, including heavy metal [ 36 ]. A computational modeling approach was used to estimate airborne lead concentrations by using BPb levels [ 37 ]. Thus, the 8-h time-weighted-average airborne lead concentrations must not exceed 2. Therefore, stringent PEL and personal hygiene strategy should be considered to reduce exposure to airborne lead. Our study found that female workers had lower lead effect dose than male workers, suggesting that, compared to males, female workers are likely to have a higher risk of lead-induce anemia.
In Taiwan, the Occupational Safety and Health Act suggests that pregnant women should stop working in the current lead-exposed workplace and prohibits them to work until one year after childbirth. This study applied the model averaging method to integrate BMD estimates across multiple models. It has been used as an effective method for estimating the model uncertainty in BMD estimation. The model averaging method has also been widely applied to dichotomous dose-response relationships in a variety of risk assessment contexts such as occupational and epidemiological studies [ 38 , 39 ].
However, several limitations may affect the accuracy of BMD estimation. The observed average BPb levels were much lower than the current health management limits in this study. However, this study still found some workers with hematological effects even though the BPb were under the permissible level.
It would be better to establish a new occupational strategy and enhance the education and training to reduce the BPb concentrations and subsequent hematotoxicity. Show More. Login Register. We want you to take advantage of everything Cancer Therapy Advisor has to offer.
To view unlimited content, log in or register for free. Register now at no charge to access unlimited clinical news, full-length features, case studies, conference coverage, and more. At a Glance Lead poisoning can cause anemia. In addition, what follow-up tests might be useful? In particular, does your patient take any medications - OTC drugs or Herbals - that might affect the lab results?
Please login or register first to view this content. Open Next post in LabMed Close. Autoimmune Hemolytic Anemias. The patient presented the kind of characteristics of abdominal pain caused by CLP. Lead is an electropositive metal with high affinity for sulfhydryl groups and thus inhibits sulfhydryl-dependent enzymes. In particular, lead also changes the vasomotor action of smooth muscle due to its effect on Ca-ATPase, which can cause abdominal pain [ 7 ].
Finally, anemia occurs, and bilirubin levels increase [ 8 ]. They are caused by a reaction between circulating lead with sulfur ions released during oral bacterial activity, which deposits lead sulfide at the junction of the teeth and gums [ 9 ]. The normal features of CLP include abdominal pain, anemia with basophilic stippling of red cells, blue-black gum deposits, and a lead line on joint radiography [ 10 ].
In conclusion, CLP is not a common cause of adult abdominal pain, the diagnosis of CLP is often delayed, and the abdominal pain can more easily conceal the underlying illnesses, detailed history taking and physical examination are crucial in early diagnosis and treatment. This report indicates that CLP should be considered as a differential diagnosis in cases of unexplained abdominal pain when other common causes have been excluded.
The diagnosis of CLP is easy once it is suspected, this study may provide more clinical experience for diagnosis of CLP. Evaluation, diagnosis, and treatment of lead poisoning in a patient with occupational lead exposure: a case presentation.
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Am J Ind Med. Download references. You can also search for this author in PubMed Google Scholar. Correspondence to Xuemei Liu. The written informed consent was obtained from the patient for publication of this report and any accompanying images.
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