Vihra V. Gocheva

Manganese exposure and cognitive deficits: A growing concern for manganese neurotoxicity

This symposium comprised five oral presentations dealing with recent findings on Mn-related cognitive and motor changes from epidemiological studies across the life span. The first contribution highlighted the usefulness of functional neuroimaging of the central nervous system (CNS) to evaluate cognitive as well as motor deficits in Mn-exposed welders. The second dealt with results of two prospective studies in Mn-exposed workers or welders showing that after decrease of Mn exposure the outcome of reversibility in adverse CNS effects may differ for motor and cognitive function and, in addition the issue of plasma Mn as a reliable biomarker for Mn exposure in welders has been addressed. The third presentation showed a brief overview of the results of an ongoing study assessing the relationship between environmental airborne Mn exposure and neurological or neuropsychological effects in adult Ohio residents living near a Mn point source. The fourth paper focused on the association between blood Mn and neurodevelopment in early childhood which seems to be sensitive to both low and high Mn concentrations. The fifth contribution gave an overview of six studies indicating a negative impact of excess environmental Mn exposure from air and drinking water on childrens cognitive performance, with special attention to hair Mn as a potential biomarker of exposure. These studies highlight a series of questions about Mn neurotoxicity with respect to cognitive processes, forms and routes of exposure, adequate biomarkers of exposure, gender differences, susceptibility and exposure limits with regard to age.

Gender differences in probable posttraumatic stress disorder among police responders to the 2001 World Trade Center terrorist attack

BACKGROUND Police responders to the 2001 World Trade Center (WTC) disaster were previously reported to have an increased prevalence of probable posttraumatic stress disorder (PTSD). METHODS Four thousand seventeen police responders (3,435 men and 582 women) were interviewed 2-3 years after 9/11/01 as part of the World Trade Center Health Registry. Demographic, occupational, and event-specific risk factors were evaluated for probable PTSD, determined by DSM-IV criteria using the Posttraumatic Stress Checklist (PCL). RESULTS Overall prevalence of probable PTSD was 8.3% (women: 13.9%; men: 7.4%, P < 0.001). Risk factors for both genders included 9/11-related injury and older age. For men, specific risk factors were: presence in WTC Towers on 9/11 and Hispanic ethnicity; and for women, witnessing horror and education less than a college degree. CONCLUSIONS Significantly higher prevalence of probable PTSD was found for female police responders. Although consistent with civilian populations, this finding contrasts with other studies of PTSD and WTC rescue and recovery workers, and police prior to 9/11.

Anxiety affecting parkinsonian outcome and motor efficiency in adults of an Ohio community with environmental airborne manganese exposure.

Manganese (Mn) is a nutrient and neurotoxicant sometimes associated with mood, motor and neurological effects. Reports of health effects from occupational exposure to Mn are well known, but the reported links to environmental airborne Mn (Mn-Air) are less conclusive. Marietta, OH (USA) is a previously identified community with elevated Mn-Air from industrial emissions. Households were randomly selected in Marietta and the comparison town (Mount Vernon, OH). The responders were used to recruit on a voluntary basis 30- to 75-year-old residents, i.e. 100 in Marietta and 90 in Mount Vernon. They were administered the Unified Parkinsons Disease Rating Scale (UPDRS), motor efficiency, and mood tests, along with a comprehensive questionnaire including demographics, health and work history. Blood Mn (MnB), serum ferritin, and hepatic enzymes were measured. Results were compared with those of 90 residents from a demographically similar comparison town, Mount Vernon, OH, where Mn-Air from industrial emissions was not of concern. Mn-Air exposure indices were modeled for Marietta residents. The Mn-exposed participants resided on average 4.75 miles (range 1-11) from the Mn point source. Their modeled residential Mn-Air estimate ranged from 0.04 to 0.96 μg/m(3) and was on average 0.18 μg/m(3). The group means of MnB were similar for the Mn-exposed (9.65 μg/L) and comparison (9.48 μg/L) participants. The Marietta group reported more generalized anxiety on the Symptom Checklist-90-Revised (SCL-90-R) than the comparison group (p=0.035). Generalized anxiety in Marietta was related to a cumulative exposure index (p=0.002), based on modeled Mn-Air concentration and length of residence. Higher generalized anxiety scores were related to poorer performance on UPDRS tests [adjusted relative risk (95%CI): 2.18 (1.46-3.25) for motor-related activities of daily living, 3.44 (1.48-7.98) for bradykinesia, and 1.63 (1.06-2.53) for motor/movement]. Group differences in SCL-90-R generalized anxiety between the two towns and the observed relationship between exposure indices and generalized anxiety suggest an association between environmental Mn exposure and anxiety states. Whether this association is due to direct neurotoxic effects of Mn-Air or concern about the health effects of air pollution remains an open question. The results highlight the importance of measuring anxiety in relation to neuropsychological and neurological endpoints, and should be validated in other studies of Mn-exposed communities.

Environmental exposure to manganese in air: Associations with cognitive functions

Manganese (Mn), an essential element, can be neurotoxic in high doses. This cross-sectional study explored the cognitive function of adults residing in two towns (Marietta and East Liverpool, Ohio, USA) identified as having high levels of environmental airborne Mn from industrial sources. Air-Mn site surface emissions method modeling for total suspended particulate (TSP) ranged from 0.03 to 1.61 μg/m(3) in Marietta and 0.01-6.32 μg/m(3) in East Liverpool. A comprehensive screening test battery of cognitive function, including the domains of abstract thinking, attention/concentration, executive function and memory was administered. The mean age of the participants was 56 years (±10.8 years). Participants were mostly female (59.1) and primarily white (94.6%). Significant relationships (p<0.05) were found between Mn exposure and performance on working and visuospatial memory (e.g., Rey-O Immediate β=-0.19, Rey-O Delayed β=-0.16) and verbal skills (e.g., Similarities β=-0.19). Using extensive cognitive testing and computer modeling of 10-plus years of measured air monitoring data, this study suggests that long-term environmental exposure to high levels of air-Mn, the exposure metric of this paper, may result in mild deficits of cognitive function in adult populations.

Chronic probable ptsd in police responders in the world trade center health registry ten to eleven years after 9/11

BACKGROUND Police enrolled in the World Trade Center Health Registry (WTCHR) demonstrated increased probable posttraumatic stress disorder (PTSD) after the terrorist attack of 9/11/2001. METHODS Police enrollees without pre-9/11 PTSD were studied. Probable PTSD was assessed by Posttraumatic Stress Check List (PCL). Risk factors for chronic, new onset or resolved PTSD were assessed using multinomial logistic regression. RESULTS Half of police with probable PTSD in 2003-2007 continued to have probable PTSD in 2011-2012. Women had higher prevalence of PTSD than men (15.5% vs. 10.3%, P = 0.008). Risk factors for chronic PTSD included decreased social support, unemployment, 2+ life stressors in last 12 months, 2+ life-threatening events since 9/11, 2+ injuries during the 9/11 attacks, and unmet mental health needs. CONCLUSION Police responders to the WTC attacks continue to bear a high mental health burden. Improved early access to mental health treatment for police exposed to disasters may be needed.

Characterization of air manganese exposure estimates for residents in two Ohio towns.

This study was conducted to derive receptor-specific outdoor exposure concentrations of total suspended particulate (TSP) and respirable (dae ≤ 10 µm) air manganese (air-Mn) for East Liverpool and Marietta (Ohio) in the absence of facility emissions data, but where long-term air measurements were available. Our “site-surface area emissions method” used U.S. Environmental Protection Agency’s (EPA) AERMOD (AMS/EPA Regulatory Model) dispersion model and air measurement data to estimate concentrations for residential receptor sites in the two communities. Modeled concentrations were used to create ratios between receptor points and calibrated using measured data from local air monitoring stations. Estimated outdoor air-Mn concentrations were derived for individual study subjects in both towns. The mean estimated long-term air-Mn exposure levels for total suspended particulate were 0.35 μg/m3 (geometric mean [GM]) and 0.88 μg/m3 (arithmetic mean [AM]) in East Liverpool (range: 0.014–6.32 μg/m3) and 0.17 μg/m3 (GM) and 0.21 μg/m3 (AM) in Marietta (range: 0.03–1.61 μg/m3). Modeled results compared well with averaged ambient air measurements from local air monitoring stations. Exposure to respirable Mn particulate matter (PM10; PM <10 μm) was higher in Marietta residents. Implications: Few available studies evaluate long-term health outcomes from inhalational manganese (Mn) exposure in residential populations, due in part to challenges in measuring individual exposures. Local long-term air measurements provide the means to calibrate models used in estimating long-term exposures. Furthermore, this combination of modeling and ambient air sampling can be used to derive receptor-specific exposure estimates even in the absence of source emissions data for use in human health outcome studies.

Police officers who responded to 9/11: Comorbidity of PTSD, depression, and anxiety 10-11 years later.

BACKGROUND After the 9/11/2001 World Trade Center (WTC) attack, many police-responders developed PTSD and might be vulnerable to develop depression and/or anxiety. Comorbidity of PTSD, depression, and/or anxiety is examined. METHOD Police enrollees (N = 1,884) from the WTC Health Registry were categorized into four groups based on comorbidity of PTSD, depression, and anxiety. DSM-IV diagnostic criteria for PTSD were used. Depression (PHQ-8) and anxiety (GAD-7) were assessed with standardized psychometric inventories. Multinomial logistic regression was used to identify putative risk factors associated with comorbidity of PTSD. RESULTS Of 243 (12.9% of total) police with probable PTSD, 21.8% had probable PTSD without comorbidity, 24.7% had depression, 5.8% had anxiety, and 47.7% had comorbid depression and anxiety. Risk factors for comorbid PTSD, depression, and anxiety include being Hispanic, decrease in income, experiencing physical injury on 9/11, experiencing stressful/traumatic events since 9/11, and being unemployed/retired. CONCLUSION Nearly half of police with probable PTSD had comorbid depression and anxiety. Am. J. Ind. Med. 59:425-436, 2016.

Posttraumatic Stress Disorder, Gender, and Risk Factors: World Trade Center Tower Survivors 10 to 11 Years After the September 11, 2001 Attacks

Ten to eleven years after the September 11, 2001 terrorist attacks, probable posttraumatic stress disorder (PTSD) was evaluated in 1,755 World Trade Center (WTC) evacuees based on data from the WTC Health Registry. Characteristics of men and women were compared and factors associated with PTSD symptom severity were examined using the PTSD Checklist (PCL). Compared with men (n = 1,015, 57.8%), women (n = 740, 42.2%) were younger and of lower socioeconomic status. Ten to eleven years after September 11, 2001, 13.7% of men and 24.1% of women met criteria for PTSD. Results indicated that when considered with all other variables (i.e., demographic, socioeconomic and social resources, exposure to the attacks, life events), gender was not a significant predictor of PTSD symptom severity. Being younger on September 11, 2001, unemployed, less educated, and/or having higher exposure to the attacks, unmet mental health care needs, and less social support predicted higher PCL scores for both genders (βs = .077 to .239). Demographic characteristics and socioeconomic resources (ΔR2 = .113) accounted for the largest amount of variance in PCL scores over and above exposure/evacuation, mental healthcare needs, and social support variables (ΔR2 = .093 to .102). When trends of unmet mental healthcare needs were analyzed, the most prevalent response for men was that they preferred to manage their own symptoms (15.1%), whereas the most prevalent response for women was that they could not afford to pay for mental health care (14.7%). Although the prevalence of probable PTSD in women tower survivors was approximately twice as high as it was for men, this is attributable largely to demographic and socioeconomic resource factors and not gender alone. Implications for treatment and interventions are discussed.

Medication use associated with exposure to manganese in two Ohio towns.

Abstract This report describes the use of medications as a proxy when medical record reviews are unavailable, to study the health effects of residents environmentally exposed to air-manganese (n = 185) compared to unexposed residents (n = 90). Participants’ current medication lists and medication questionnaire responses were collected in clinical interviews and categorized into 13 domains. Exposed participants reported fewer hours of sleep than controls (6.6 vs. 7.0). The exposed used significantly more medications than unexposed participants (82.2 % vs. 67.8 %) and, when adjusting for age, education, and personal income, also for pain (aOR = 2.40) and hypothyroidism (aOR = 7.03). Exposed participants with higher air-Mn concentrations, monitored for 10 years by the U.S. Environmental Protection Agency, were 1.5 times more likely to take pain medications. The exposed participants take significantly more medications than unexposed participants in the categories of hypothyroidism, pain, supplements, and total medications.

Response to: Comment on “Environmental exposure to manganese in air: Associations with tremor and motor function” by Bowler et al. 2016

a San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA b Colorado State University, 1879 Campus Delivery, Fort Collins, CO 80523, USA c Agency for Toxic Substances and Disease Registry, Region 5, 77W. Jackson Blvd., MS ATSD-4J, Chicago, IL 60604, USA d U.S. EPA Region 5, 77W. Jackson Blvd., AR 18-J, Chicago, IL 60604, USA e Ulsan University Hospital, University of Ulsan College of Medicine, Department of Occupational and Environmental Medicine, Ulsan 682-060, South Korea f U.S. EPA, National Health and Environmental Effects Research Laboratory, MD 58A, Research Triangle Park, NC 27711, USA