Ti-containing NPs in raw water and their removal with conventional treatments in four water treatment plants in Taiwan.

The ingestion of Ti-containing nanoparticles from drinking water has emerged as a concern in recent years. This study therefore aimed to characterize Ti-containing nanoparticles in water samples collected from four water treatment plants in Taiwan and to explore the challenges associated with measuring them at low levels using single particle-inductively coupled plasma mass spectrometry. Additionally, the study sought to identify the most effective processes for the removal of Ti-containing nanoparticles. For each water treatment plant, two water samples were collected from raw water, sedimentation effluent, filtration effluent, and finished water, respectively. Results revealed that Ti-containing nanoparticles in raw water, with levels at 8.69 µg/L and 296.8 × 103 particles/L, were removed by approximately 35% and 98%, respectively, in terms of mass concentration and particle number concentration, primarily through flocculation and sedimentation processes. The largest most frequent nanoparticle size in raw water (112.0 ± 2.8 nm) was effectively reduced to 62.0 ± 0.7 nm in finished water, while nanoparticles in the size range of 50-70 nm showed limited changes. Anthracite was identified as a necessary component in the filter beds to further improve removal efficiency at the filtration unit. Moreover, the most frequent sizes of Ti-containing nanoparticles were found to be influenced by salinity. Insights into the challenges associated with measuring low-level Ti-containing nanoparticles in aqueous samples provide valuable information for future research and management of water treatment processes, thereby safeguarding human health.

Temporal transition trends of cord blood lead levels in various human development index countries and in the Taipei metropolitan area.

Since low-level lead exposure is still of concern for neonates, it is worth further characterizing the temporal transition trends of cord blood lead levels (CBLLs) globally and locally in Taipei, Taiwan, after the cessation of leaded gasoline use. A literature review on CBLLs around the world was performed by searching three databanks, i.e., PubMed, Google Scholar and Web of Science, with the search keywords "cord blood" combined with "lead" or "Pb" for studies published from 1975 to May 2021. In total, 66 articles were included. Linear regressions for the reciprocal of sample size weighed CBLLs against calendar year presented a high r2 value (0.722) for the very high Human Development Index (HDI) countries and a moderate r2 value (0.308) for the combined high and medium HDI countries. The predicted CBLLs in 2030 and 2040 were 6.92 (95% CI: 6.02-7.81) µg/L and 5.85 (95% CI: 5.04-6.66) µg/L, respectively, for the very high HDI countries and 13.10 (95% CI: 7.12-19.09) µg/L and 10.63 (95% CI: 5.37-15.89) µg/L, respectively, for the combined high and medium HDI countries. To characterize the CBLL transitions in the Great Taipei metropolitan area, data from five studies conducted from 1985 to 2018 were employed. Although the results of the early four studies indicated that the Great Taipei metropolitan area did not reach the pace in CBLL reduction among the very high HDI countries, the CBLLs of the latest study during 2016-2018 were pretty low (8.1 ± 4.5 µg/L), approximately 3 years in advance of the very high HDI countries as one group to reach this low CBLL. In conclusion, further effective reduction in environmental lead exposure is challenging and must be based on the efforts from the aspects reflected by the HDI index compositions, i.e., economics, education and health, mostly implying health disparity and inequality.

Impact of age on the postural stability measured by a virtual reality tracker-based posturography and a pressure platform system.

BACKGROUND: Center of pressure (CoP) parameters are commonly used to evaluate age-related changes in postural control during standing. However, they mainly reflect ankle strategies and provide limited information about hip strategies, which are essential for postural control among the aged population. Body displacement at the lumbar level (LD) can be used as a proxy for hip strategies. OBJECTIVES: We set up a virtual reality tracker-based posturography to measure LD and compared the CoP and LD parameters in two age groups to explore the roles of ankle and hip strategies during bipedal stance. METHODS: Twenty-seven older healthy participants (63.8 ± 7.1 years old) and 27 younger controls (31.7 ± 9.9 years old) performed four standing tasks with their postural steadiness measured simultaneously with both systems under four stance conditions (combination of eyes-open/eyes-closed and wide-based/narrow-based). Five parameters were calculated from the trajectories of the CoP and LD. The difference in the parameters between two groups was analyzed with the Mann-Whitney U test. The discriminative ability of the parameters from the two systems was computed by the receiver operating characteristic curve analysis and area under the curve (AUC). We also used the intraclass correlation coefficient (ICC) to assess the correlation between two measures. RESULTS: Most of the parameters obtained from both systems were significantly different between the younger and older groups. Mean velocity in the medial-lateral and anterior-posterior directions could effectively discriminate age-related changes, especially with the LD parameters. The receiver's operation curve analysis gained the largest AUC (0.85 with both systems) with mean velocity in the medial-lateral direction during narrow-based standing with eyes closed. Meanwhile, we observed a low correlation between parameters obtained from the two methods in velocity measures, with the lowest ICC in the mean velocity in the medial-lateral direction in the older group (ICC = 0.34 ~ 0.41). CONCLUSION: Both systems could differentiate age-related changes in postural steadiness, but with dissociated information about mean velocity, especially the mean velocity in the medial-lateral direction in the older group. The results support the complimentary role of using tracker-based posturography to understand the effect of age on the mechanisms of postural control.

Characterization of Ti-containing nanoparticles in the aquatic environment of the Tamsuei River Basin in northern Taiwan.

Titanium dioxide (TiO2) is commonly contained in many commercial products and there are concerns about its release into the aquatic environment after use. This study was designed to characterize the distribution of Ti-containing nanoparticulates (NPs) in the water of the Tamsuei River Basin in northern Taiwan. Water samples were collected from the upstream, mid-stream, and downstream areas of the Tamsuei River Basin and analyzed with single-particle ICPMS to profile the Ti-containing NPs in terms of mass concentration, number concentration and particulate size. The lowest mass concentration of Ti-containing NPs, 1.04 ± 0.04 µg/L, was found in the upstream water samples, while the highest mass concentration, 31.7 ± 0.6 µg/L, was observed in downstream samples; there was an increasing trend from upstream to downstream. The highest particulate number concentration, 479 ± 163 × 103/mL, was observed for the downstream samples, but the lowest concentration, 45.4 ± 5.6 × 103/mL, was found in the mid-stream water samples taken from Site C. Moreover, the average mode values for particulate sizes were approximately 50 nm for all samples, although a relatively larger average mode value of 62 ± 5.7 nm was observed in the mid-stream samples from Site A. Increasing mass concentrations and particulate number concentrations from upstream to downstream implied that these NPs might have originally resulted from anthropogenic activities involving the use of TiO2 NPs-containing products. Surprisingly, however, the lowest number concentrations for Ti-containing NPs in the mid-stream samples can probably be attributed to the fact that the corresponding sampling sites were located in the water preservation zone, which exhibits a particle-settling effect. Additionally, the sizes of Ti-containing NPs in downstream samples were not significantly larger than those in the upstream and mid-stream samples, as expected, which was probably due to the steric effects resulting from the presence of large amounts of macromolecule polymers in aquatic environments.

The Effects of Visual Backgrounds in the Virtual Environments on the Postural Stability of Standing.

A photorealistic scene in a head mount display (HMD) is considered high fidelity and associated with postural stability similar to that in the real world, but the effects of visual background under different standing conditions have not been examined. Thirty-four healthy adults performed four standing (standardized, narrow, tandem and one-leg) tasks in three scenes with an HMD, while viewing one of three scenes: a real room (real scene, RS), a photorealistic scene (VrS) and a blank scene (BS). The effects of the visual scenes and standing tasks on sway parameters were analyzed. Romberg quotients (RQs) of the sway parameters were compared between RS and VrS with reference to BS to compare visual contribution to posture stability. Sway parameters were similar during all three scenes during the standardized and narrow standing tasks, but higher in VrS and BS conditions than in the RS condition during the tandem and one-leg standing tasks. The effects of visual scenes on postural stability showed a significant interaction with the standing tasks. The BS/VsR and BS/RS ratios were close to 1.0 for the standardized and narrow standing tasks, and the magnitude of increase was lower for BS/VsR than BS/RS during the tandem and one-leg standing tasks, indicating different levels of visual dependence. The effects of virtual scenes on postural stability were task-dependent. Adjusting the amount of visual stimuli and choosing tasks with higher postural demands may result in synergic effects, but the influence of visual environments should be examined with consideration of visual targeting.

Reliability and Validity of a Virtual Reality-Based System for Evaluating Postural Stability.

Postural stability is an important indicator of balance and is commonly evaluated in neurorehabilitation. We proposed a system based on a virtual reality (HTC Vive) system with a tracker at the lumbar area. The position data of the tracker were obtained through detection of the sensors on the tracker by the VR system. The reliability and validity of these sway parameters to measure postural stability were evaluated. Twenty healthy adults had their postural sway measured with this system and a force platform system under four stance conditions, with wide- or narrow-stance and eyes open or closed. The path data from both systems were computed to obtain the following parameters: the mean distance and the mean velocity in the medial-lateral and anterior-posterior directions and the 95% confidence ellipse area. The reliability of the Vive-based sway measures was tested with intraclass correlation coefficients (ICCs). The convergent validity was tested against the center of pressure (COP) parameters from the force platform system. Finally, the discriminative validity was tested for the above four conditions. The results indicated that the Vive-based sway parameters had moderate to high reliability (ICCs: 0.56 ~ 0.90) across four conditions and correlated moderately to very highly with the COP parameters ( r = 0.420  âˆ¼  0.959 ). Bland-Altman plotting showed generally good agreement, with negative offset for the Vive-based sway parameters. The sway parameters obtained by the Vive-based system also discriminated well among the tasks. In conclusion, the results support this system as a simple and easy-to-use tool to evaluate postural stability with acceptable reliability and validity.

Globally temporal transitions of blood lead levels of preschool children across countries of different categories of Human Development Index.

In the past decades, efforts to eliminate lead from gasoline, paint and drinking water around the world have substantially reduced human blood lead levels. This study was therefore aimed at examining the global temporal trends in the blood lead levels of preschool children by the category of UN Human Development Index (HDI). In total, 103 blood lead records were retrieved from 51 articles searched from PubMed and Google Scholar, with study subjects aged up to 8years old. Collected preschool children blood lead levels were plotted chronologically by HDI category and their reciprocals were used in regression analysis against calendar year to establish their temporal transition trends in the past decades. Results show that the modes of blood lead level of the preschool children were reduced from 4-6µg/dL to 0.8-1.5µg/dL, from 6-15µg/dL to 3-6µg/dL and from 12-16 to 5-6µg/dL for the very high HDI countries, the high HDI countries and the medium/low HDI countries, respectively. The highest correlation coefficient, 0.849, between the reciprocal of blood lead level and the calendar year was found for the very high HDI countries. Based on the regression lines, the predicted preschool children mean blood lead levels in the year of 2030 are 0.74µg/dL, 2.21µg/dL and 2.86µg/dL, respectively, for the very high HDI countries, the high HDI countries and the medium/low HDI countries. Persistent differences in blood lead level prevailed among countries of different HDI category, suggesting the effects of disparities and inequalities, at the state level, on preschool children blood lead levels. Further action is warranted to reduce the already low environmental lead exposure to eliminate the developmental burden of lead on children through (1) identification of individual local factors for lead exposure and (2) averting health disparity and inequalities at the state level.

Pilot Studies of VOC Exposure Profiles during Surgical Operations.

Volatile organic chemical exposure resulting from surgical operations is common in operating room personnel. The potential risk of long-term exposure to these low-level chemicals is always a concern. This study was conducted in an area hospital located in northern Taiwan to investigate the internal exposure scenario for operating room personnel. Breath samples were collected before and after surgery, whereas area samples were collected during the surgeries in process. There were 18 volatile organic compounds identified in the samples with gas chromatography-mass spectrometry. The average concentrations of sevoflurane (P = 0.0082), dimethyl sulfide (P = 0.0550), and methyl methacrylate (P = 0.0606) in breath samples collected after surgical operations were significantly higher compared to those obtained before surgical operations, whereas only slight elevations were present for benzene and hexamethyldisiloxane (P < 0.100). In addition, electrosurgical smoke-related chemicals, such as benzene, toluene, ethylbenzene, and m/p-xylene, also presented higher levels in operating room samples compared to the control area. Specifically, the findings in this preliminary study suggested the associations of elevated exposure to sevoflurane across various surgeries to methyl methacrylate with orthopedic surgery and to hexamethyldisiloxane with conventional electrosurgical units. Future study is warranted to explore the short-term high-level chemical exposure in operating rooms and to propose effective preventive measures accordingly to keep any exposure to chemicals at the lowest practical level.

Mobile Phone Use Behaviors and Postures on Public Transportation Systems.

Mobile phones are common in our daily life, but the users' preferences for postures or screen operating styles have not been studied. This was a cross-sectional and observational study. We randomly sampled passengers who used mobile phones on the Mass Rapid Transit (MRT) system in metropolitan Taipei. A checklist was used to observe their body postures and screen operating styles while sitting or standing. As a result, 1,230 subjects from 400 trips were observed. Overall, of all the passengers who were sitting, 41% of them were using mobile phones. The majority of the tasks involved browsing (84%) with their phones in a portrait orientation (93%). Different-hand holding/operating was the most commonly used operating style while sitting (46%) and same-hand holding/operating was the most common while standing (46%). The distribution of screen operating styles was significantly different for those sitting than for those standing and for different genders and age groups. The most frequently observed postures while sitting were having one's trunk against a backrest, feet on the floor and with or without an arm supported (58%). As for the users who were standing, the both- and different-hands groups had a high proportion of arms unsupported, feet on the floor and either their trunk supported or not. In contrast, the same-hand group tended to have their trunk unsupported, were holding a pole or handstrap and had both feet on floor. Further studies are warranted to characterize the ergonomic exposure of these commonly used postures and operating styles, and our results will help guide the selection of experimental conditions for laboratory settings.

Increased inflammation in rheumatoid arthritis patients living where farm soils contain high levels of copper.

BACKGROUND/PURPOSE: Heavy metal pollution in farm soils is a problem in some parts of Taiwan. Copper can be a factor associated with increased disease activities of rheumatoid arthritis (RA). Thus, the aim of this study was to investigate whether copper pollution in farm soils is associated with worsened RA. METHODS: Clinical parameters from 122 RA patients were collected from a medical center in central Taiwan. Levels of heavy metals in the blood were measured using inductively coupled plasma mass spectrometry. Levels of copper in farm soils were retrieved from a national survey. These data were analyzed to find the factors related to RA disease activities. RESULTS: RA patients living where farm soils contained high levels of copper had increased white blood cell counts, erythrocyte sedimentation rate, and disease activity score 28, compared with patients living where copper levels were low. Among the nine types of heavy metal measured in the study, blood levels of copper and nickel correlated with erythrocyte sedimentation rate. CONCLUSION: Our cross-sectional data suggest a correlation between RA disease activity and the level of copper at township farm soils samples. Further longitudinal studies using more rigorous methodologies are warranted to examine whether this correlation is causal.

Influence of smartphone use styles on typing performance and biomechanical exposure.

Twenty-seven subjects completed 2-min typing tasks using four typing styles: right-hand holding/typing (S-thumb) and two-hand typing at three heights (B-low, B-mid and B-high). The styles had significant effects on typing performance, neck and elbow flexion and muscle activities of the right trapezius and several muscles of the right upper limb (p < 0.0001 by repeated-measure analysis of variance). The subjects typed the fewest words (error-adjusted characters per minute: 78) with the S-thumb style. S-thumb style resulted in similar flexion angles of the neck, elbow and wrist, but significantly increased muscle activities in all tested muscles compared with the B-mid style. Holding the phone high or low reduced the flexion angles of the neck and right elbow compared with the B-mid style, but the former styles increased the muscle activity of the right trapezius. Right-hand holding/typing was not a preferable posture due to high muscle activities and slow typing speed. Practitioner Summary: Right-hand holding/typing was not favoured, due to increased muscle activities and slower typing speed. Holding the phone high or low reduced the flexion angles of the neck and right elbow, but the former styles increased the muscle activity of the right trapezius compared with holding the phone at chest level.

Mercury, APOE, and child behavior.

Methylmercury (MeHg) is a neurotoxicant and may have an adverse impact on child behavior. However, this impact was found to be inconsistent in fish-eating populations. Although the positive effects of the nutrients provided by a fish diet may overcome the effect of MeHg, the possibility of genetic variants influencing an individual's response to MeHg has also been discussed. The role of the Apolipoprotein E (APOE) epsilon 4 allele (ε4) on MeHg related neurotoxicity is still unclear. In the present study, we investigated the role of APOE variants in the relationship between cord blood mercury (Hg) and child behavior. A total of 166 subjects were recruited at delivery, and their cord blood was collected for laboratory analyses of Hg and the APOE genotype. The Child Behavior Checklist (CBCL) was administered to the subjects when they reached the age of two years. An increase in cord blood Hg concentrations in APOE ε4 carriers was consistently associated with an increased score for all CBCL syndromes. After controlling for potential confounding factors, the group of ε4 carriers with an elevated cord blood Hg concentration had significantly higher scores in the syndrome categories of general internalizing, emotionally reactive, and anxiety/depression as well as CBCL total scores. Furthermore, general externalizing and aggressive syndromes were borderline significantly higher in this group. In conclusion, we suggest that APOE may modify the toxicity of MeHg. APOE ε4 carriers may be more vulnerable to the effects of MeHg on child behavior at the age of two years.

Incense burning at home and the blood lead level of preschoolers in Taiwan.

The growth and intellectual development of children less than 6 years old may be affected by exposure to low levels of lead. To further reduce environmental lead exposure, this study examined possible household-related factors that affect the blood lead levels of Taiwanese children. In total, based on a stratified random sampling strategy, 934 kindergarten students were recruited throughout Taiwan from April to October 2011 after their parents signed a statement of consent. A venous blood sample was drawn from each participant and analyzed for lead content using inductively coupled plasma mass spectrometry. Information on the demographics and household environment of the study subjects was collected by administering a questionnaire (Table 1). The geometric mean lead level in the blood samples of the study subjects was 1.84 µg/dL with a geometric standard deviation of 1.55. The blood lead level was negatively correlated with household income and parental educational levels (p < 0.0001). Study subjects with more siblings also tended to have higher blood lead levels (p < 0.0001). Incense burning in the home, an ethnic tradition, was also identified as a significant factor for increased blood lead levels (p < 0.0003) and demonstrated a dose-dependent relationship with frequency of incense burning at home (p = 0.0022). Because the health effects of low levels of lead exposure have been reported in recent years and because no consensus has been reached regarding a safety threshold for blood lead level in children, any trivial factor is worth investigating to further prevent lead exposure in children. Incense burning at home is a common traditional religious activity in Taiwan; therefore, more study is warranted to further eliminate the lead content in incense and reduce lead exposure for the families who practice this activity.

Psychiatric disorders after occupational injury among National Health Insurance enrollees in Taiwan.

This study aimed to determine the incidence rates of psychiatric disorders within 1 year after occupational injury and to examine the association between occupational injury and the incidence of psychiatric disorders using National Health Insurance Research Database (NHIRD). We used cohort approach in this investigation. All eligible subjects were from the NHIRD, and aged 18-65 years old. A total of 542,208 patients were enrolled in this study. Among them, 1038 patients sustained occupational injury, 6891 patients sustained non-occupational injury. The reference group in this study was 534,279 patients who ever used the NHI for any medical condition in 2001. The incidence rates of any psychiatric disorders within 1 year after occupational injury (inpatient), occupational injury (outpatient), non-occupational injury (inpatient), non-occupational injury (outpatient), and any disease were 9.5%, 2.5%, 7.4%, 1.5%, and 1.1%, respectively. Occupational injury was found as a significant factor for developing psychiatric disorders within 1 year after the target injury. The incidence rate of any psychiatric disorders was higher in patients after occupational injury than those after non-occupational injury and any medical condition.

The dose-response relationship between cumulative lifting load and lumbar disk degeneration based on magnetic resonance imaging findings.

BACKGROUND: Lumbar disk degeneration (LDD) has been related to heavy physical loading. However, the quantification of the exposure has been controversial, and the dose-response relationship with the LDD has not been established. OBJECTIVE: The purpose of this study was to investigate the dose-response relationship between lifetime cumulative lifting load and LDD. DESIGN: This was a cross-sectional study. METHODS: Every participant received assessments with a questionnaire, magnetic resonance imaging (MRI) of the lumbar spine, and estimation of lumbar disk compression load. The MRI assessments included assessment of disk dehydration, annulus tear, disk height narrowing, bulging, protrusion, extrusion, sequestration, degenerative and spondylolytic spondylolisthesis, foramina narrowing, and nerve root compression on each lumbar disk level. The compression load was predicted using a biomechanical software system. RESULTS: A total of 553 participants were recruited in this study and categorized into tertiles by cumulative lifting load (ie, <4.0 × 10(5), 4.0 × 10(5) to 8.9 × 10(6), and ≥8.9 × 10(6) Nh). The risk of LDD increased with cumulative lifting load. The best dose-response relationships were found at the L5-S1 disk level, in which high cumulative lifting load was associated with elevated odds ratios of 2.5 (95% confidence interval [95% CI]=1.5, 4.1) for dehydration and 4.1 (95% CI=1.9, 10.1) for disk height narrowing compared with low lifting load. Participants exposed to intermediate lifting load had an increased odds ratio of 2.1 (95% CI=1.3, 3.3) for bulging compared with low lifting load. The tests for trend were significant. LIMITATIONS: There is no "gold standard" assessment tool for measuring the lumbar compression load. CONCLUSIONS: The results suggest a dose-response relationship between cumulative lifting load and LDD.

Long-term psychological outcome of workers after occupational injury: prevalence and risk factors.

INTRODUCTION: This study aimed to examine the prevalence rates of both post-traumatic stress disorder (PTSD) and major depression at 12 months in workers experiencing different types of occupational injury in Taiwan. Demographic and injury-related risk factors for psychological symptoms were also evaluated. METHODS: Our study candidates were injured workers in Taiwan who were hospitalized for 3 days or longer and received hospitalization benefits from the Labor Insurance program. A two-staged survey study was conducted. A self-reported questionnaire including the Brief Symptom Rating Scale and Post-traumatic Symptom Checklist was sent to workers at 12 months after injury. Those who met the criteria were recruited for the second-stage phone interview with a psychiatrist using the Mini-international Neuropsychiatric Interview (MINI). RESULTS: A total of 1,233 workers completed the questionnaire (response rate 28.0 %). Among them, 167 (13.5 %) fulfilled the criteria for the MINI interview and were invited. A total of 106 (63.5 %) completed the phone interview. The estimated rate of either PTSD/PPTSD or major depression was 5.2 %. The risk factors for psychological symptoms were female gender, lower education level, loss of consciousness after occupational injury, injury affecting physical appearance, occupational injury experience before this event, life experience before and after this injury, length of hospital stay, self-rated injury severity, and percentage of income to the family. CONCLUSIONS: These results showed that occupational injury can cause long-term psychological impact in workers. Key demographic and injury characteristics may enhance the identification of at-risk occupational injured workers who would benefit from targeted screening and early intervention efforts.

Cardiopulmonary toxicity of pulmonary exposure to occupationally relevant zinc oxide nanoparticles.

Exposure to zinc oxide (ZnO) metal fumes is linked to adverse human health effects; however, the hazards of ZnO nanoparticles (ZnONPs) remain unclear. To determine pulmonary exposure to occupationally relevant ZnONPs cause cardiopulmonary injury, Sprague-Dawley rats were exposed to ZnONPs via intratracheal (IT) instillation and inhalation. The relationship between intrapulmonary zinc levels and pulmonary oxidative-inflammatory responses 72 h after ZnONP instillation was determined in bronchoalveolar lavage fluid (BALF). Instilled ZnONPs altered zinc balance and increased the levels of total cells, neutrophils, lactate dehydrogenase (LDH) and total protein in BALF and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in blood after 72 h. The ZnONPs accumulated predominantly in the lungs over 24 h, and trivial amounts of zinc were determined in the heart, liver, kidneys and blood. Furthermore, the inflammatory-oxidative responses induced by occupationally relevant levels of 1.1 and 4.9 mg/m(3) of ZnONP inhalation for 2 weeks were determined in BALF and blood at 1, 7 and 30 days post-exposure. Histopathological examinations of the rat lungs and hearts were performed. Inhalation of ZnONP caused an inflammatory cytological profile. The total cell, neutrophil, LDH and total protein levels were acutely increased in the BALF, and there was an inflammatory pathology in the lungs. There were subchronic levels of white blood cells, granulocytes and 8-OHdG in the blood. Cardiac inflammation and the development of fibrosis were detected 7 days after exposure. Degeneration and necrosis of the myocardium were detected 30 days after exposure. The results demonstrate that ZnONPs cause cardiopulmonary impairments. These findings highlight the occupational health effects for ZnONP-exposed workers.

Association of blood lead and mercury with estimated GFR in herbalists after the ban of herbs containing aristolochic acids in Taiwan.

OBJECTIVE: This study was undertaken to explore the association of estimated glomerular filtration rate (GFR) with exposure to aristolochic acids (ALAs) and nephrotoxic metals in herbalists after the ban of herbs containing ALAs in Taiwan. METHODS: This cross-sectional study recruited a total of 138 herbalists without end-stage renal disease or urothelial carcinoma from the Occupational Union of Chinese Herbalists in Taiwan in 2007. Aristolochic acid I (ALA-I) was measured by ultra-high-pressure liquid chromatography/ tandem mass spectrometry (UHPLC-MS/MS) and heavy metals in blood samples were analysed by Agilent 7500C inductively coupled plasma-mass spectrometry. Renal function was assessed by using a simplified Modification of Diet in Renal Disease Study equation to estimate GFR. RESULTS: Blood lead was higher in herbal dispensing procedures (p=0.053) and in subjects who self-prescribe herbal medicine (p=0.057); mercury was also higher in subjects living in the workplace (p=0.03). Lower estimated GFR was significantly associated with lead (ß=-10.66, 95% CI -18.7 to -2.6) and mercury (ß=-12.52, 95% CI -24.3 to -0.8) with a significant interaction (p=0.01) between mercury and lead; however, estimated GFR was not significantly associated with high ALA-I level groups, arsenic and cadmium after adjusting for other confounding factors. CONCLUSIONS: We found that lower estimated GFR was associated with blood lead and mercury in herbalists after the ban of herbs containing ALAs in Taiwan. The ALA-I exposure did not show a significant negative association of estimated GFR, which might due to herbalists having known how to distinguish ALA herbs after the banning policy. Rigorous monitoring is still needed to protect herbalists and the general population who take herbs.

In utero exposure to environmental lead and manganese and neurodevelopment at 2 years of age.

BACKGROUND AND OBJECTIVE: Manganese, lead, arsenic and mercury are common neurotoxic metals in the environment. Nonetheless, the relationship between prenatal exposure to low doses of neurotoxic metals and neurodevelopment in children is not clear. The objective of this study was to explore the relationship between in utero exposure to environmental neurotoxic metals and neurodevelopment at 2 years of age. METHODS: The population of this study came from the Taiwan Birth Panel Study. We included 230 pairs of non-smoking mothers without any occupational exposure and their singleton full-term children. The information about exposure during pregnancy was obtained using a structured questionnaire, and the manganese, lead, arsenic and mercury levels in umbilical cord blood samples were analyzed using inductively coupled plasma mass spectrometry. We used the Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT) to evaluate the developmental status of each child at 2 years of age, and we examined the association of in utero exposure to environmental metals and neurodevelopment using linear regression models. RESULTS: The median concentrations of manganese, lead, arsenic and mercury in the cord blood samples in this study were 47.90 µg/L (range, 17.88-106.85 µg/L), 11.41 µg/L (range 0.16-43.22 µg/L), 4.05 µg/L (range, 1.50-12.88 µg/L) and 12.17 µg/L (range, 1.53-64.87 µg/L), respectively. After adjusting for maternal age, infant gender, environmental tobacco smoke during pregnancy and after delivery, Home Observation for Measurement of the Environment Inventory results, and arsenic and mercury levels in cord blood, we found that manganese and lead levels above the 75th percentile had a significant adverse association with the overall (ß=-7.03, SE=2.65, P=0.0085), cognitive (ß=-8.19, SE=3.17, P=0.0105), and language quotients (ß=-6.81, SE=2.73, P=0.0133) of the CDIIT. CONCLUSIONS: In utero exposure to environmental manganese and lead may have an adverse association with neurodevelopment at 2 years of age, and there is an interaction effect between the manganese and lead levels in the cord blood that could aggravate the effect.

Mercury, APOE, and children's neurodevelopment.

The benefit of the nutritious elements in fish is insufficient for explaining the controversial finding regarding prenatal mercury (Hg) exposure and neurodevelopment; the varying frequency of susceptible genes among these populations may shed light on these observations. However, limited studies have been reported on the association between genetic susceptibility of prenatal Hg exposure and child development. Apolipoprotein E (APOE, protein; Apoe, gene) is a major protein transporter expressed in the brain. The Apoe epsilon 4 (ε4) allele is associated with poor neural repair function and is a risk factor associated with Alzheimer disease. We conducted a prospective cohort study in 2004 and 2005. In this study, 168 subjects were recruited at delivery and followed up at two years of age, and genetic polymorphisms of Apoe were included to assess genetic susceptibility and to determine the relationship between Hg concentrations in cord blood and neurodevelopment. The results showed that adverse effects on neurodevelopment were consistently associated with prenatal Hg exposure in all subtests of Comprehensive Developmental Inventory for Infants and Toddlers (CDIIT) among ε4 carriers as assessed by both simple linear and multiple linear regression models. After controlling for confounding factors, statistical significance was found in the subtests of cognition tests (ß=-8.47, 95% confidence interval (CI)=-16.10 to -0.84), social tests (ß=-11.02, 95% CI=-20.85 to -1.19) and the whole test of CDIIT (ß=-10.45, 95% CI=-17.36 to -3.54) in a multiple linear regression model. Additionally, the interaction effect between gene polymorphisms of Apoe and Hg levels was significant in the whole test CDIIT and subtests of cognition, language and fine motor tests. In conclusion, Apoe modifies the adverse effects of cord blood Hg on neurodevelopment at the age of two years.