Biomedical subjects

Misty J Hein

Publications and source records attributed to Misty J Hein.

12 recordsLinked to original sources

PubMed2006

Urinary pesticide concentrations among children, mothers and fathers living in farm and non-farm households in iowa.

In the spring and summer of 2001, 47 fathers, 48 mothers and 117 children of Iowa farm and non-farm households were recruited to participate in a study investigating take-home pesticide exposure. On two occasions approximately 1 month apart, urine samples from each participant and dust samples from various rooms were collected from each household and were analyzed for atrazine, metolachlor, glyphosate and chlorpyrifos or their metabolites. The adjusted geometric mean (GM) level of the urine metabolite of atrazine was significantly higher in fathers, mothers and children from farm households compared with those from non-farm households (P < or = 0.0001). Urine metabolites of chlorpyrifos were significantly higher in farm fathers (P = 0.02) and marginally higher in farm mothers (P = 0.05) when compared with non-farm fathers and mothers, but metolachlor and glyphosate levels were similar between the two groups. GM levels of the urinary metabolites for chlorpyrifos, metolachlor and glyphosate were not significantly different between farm children and non-farm children. Farm children had significantly higher urinary atrazine and chlorpyrifos levels (P = 0.03 and P = 0.03 respectively) when these pesticides were applied by their fathers prior to sample collection than those of farm children where these pesticides were not recently applied. Urinary metabolite concentration was positively associated with pesticide dust concentration in the homes for all pesticides except atrazine in farm mothers; however, the associations were generally not significant. There were generally good correlations for urinary metabolite levels among members of the same family.

Acetamides↗

PubMed2006

Update: cohort mortality study of workers highly exposed to polychlorinated biphenyls (PCBs) during the manufacture of electrical capacitors, 1940-1998.

BACKGROUND: The National Institute for Occupational Safety and Health previously reported mortality for a cohort of workers considered highly exposed to polychlorinated biphenyls (PCBs) between 1939 and 1977 at two electrical capacitor manufacturing plants. The current study updated vital status, examined liver and rectal cancer mortality previously reported in excess in this cohort and evaluated mortality from non-Hodgkin's lymphoma (NHL) and cancers of the stomach, intestine, breast, prostate, skin (melanoma) and brain reported to be in excess in other cohort and case-control studies of PCB-exposed persons. METHODS: Mortality was updated through 1998 for 2572 workers. Age-, gender-, race- and calendar year-adjusted standardized mortality ratios (SMRs) and 95% confidence intervals (CI) were calculated using U.S., state and county referent rates. SMRs using U.S. referent rates are reported. Duration of employment was used as a surrogate for exposure. RESULTS: Consistent with the previous follow-up, mortality from biliary passage, liver and gall bladder cancer was significantly elevated (11 deaths, SMR 2.11, CI 1.05 - 3.77), but mortality from rectal cancer was not (6 deaths, SMR 1.47, CI 0.54 - 3.21). Among women, mortality from intestinal cancer (24 deaths, SMR 1.89, CI 1.21 - 2.82) and from "other diseases of the nervous system and sense organs", which include Parkinson's disease and amyotrophic lateral sclerosis, (15 deaths, SMR 2.07, CI 1.16 - 3.42) were elevated. There were four ALS deaths, all women (SMR 4.35, CI 1.19-11.14). Mortality was elevated for myeloma (7 deaths, SMR 2.11, CI 0.84 - 4.34), particularly among workers employed 10 years or more (5 deaths, SMR 2.80, CI 0.91 - 6.54). No linear associations between mortality and duration of employment were observed for the cancers of interest. CONCLUSION: This update found that the earlier reported excess in this cohort for biliary, liver and gall bladder cancer persisted with longer follow-up. Excess mortality for intestinal cancer among women was elevated across categories of duration of employment; myeloma mortality was highest among those working 10 years or more. The small numbers of deaths from liver and intestinal cancers, myeloma and nervous system diseases coupled with the lack of an exposure-response relationship with duration of employment preclude drawing definitive conclusions regarding PCB exposure and these causes of death.

Aged↗

PubMed2006

Mortality of workers employed in shoe manufacturing: an update.

BACKGROUND: In the late 1970s, the National Institute for Occupational Safety and Health identified two shoe manufacturing facilities where workers experienced relatively "pure" exposures to toluene. A mortality study was conducted through December 31, 1982. An original study did not detect elevated leukemia mortality but did detect increased lung cancer mortality. The present study is an update of the mortality of the original cohort. METHODS: The study cohort consisted of workers employed 1 month or more between 1940 and 1979 at two Ohio shoe manufacturing plants. Vital status was ascertained through December 31, 1999. RESULTS: Seven thousand eight hundred twenty eight workers, contributing 300,777 person years, were available for analysis. An excess of lung cancer deaths persisted with additional years of follow-up (SMR = 1.36, 95% confidence interval (CI) = 1.19-1.54). Trend tests did not indicate a positive trend between lung cancer risk and duration of employment. Mortality from leukemia was not significantly elevated in the updated analysis. CONCLUSIONS: Results indicate a possible association between lung cancer mortality and exposure to chronic, low-levels of organic solvents. Although the strength of this conclusion was weakened by the lack of increasing lung cancer risk in relation to duration of employment, other studies have supported this association.

Adolescent↗

PubMed2006

Polychlorinated biphenyls and neurodegenerative disease mortality in an occupational cohort.

BACKGROUND: Production of polychlorinated biphenyls (PCBs) ended in the United States in the 1970s, but PCBs persist in the environment and are detectable in the blood of approximately 80% of Americans over age 50. PCBs decrease dopamine levels in rats and monkeys. Loss of dopamine is the hallmark of Parkinson disease, a neurodegenerative disease. There are no epidemiologic studies of PCBs and neurodegenerative disease. METHODS: We conducted a retrospective mortality study of 17,321 PCB-exposed workers to determine whether mortality from Parkinson disease, dementia, and amyotrophic lateral sclerosis was elevated compared with the U.S. population. All workers had a least 90 days employment in 1 of 3 electrical capacitor plants using PCBs from the 1940s to the 1970s. PCB serum levels from a sample of these workers in the 1970s were approximately 10 times the level of community controls. RESULTS: We found no overall excess of Parkinson disease, amyotrophic lateral sclerosis, or dementia in the PCB-exposed cohort (standardized mortality ratios [SMRs]-1.40, 1.11, and 1.26, respectively, and number of deaths-14, 10, and 28 respectively). However, sex-specific analyses revealed that women had an excess of amyotrophic lateral sclerosis (SMR-2.26; 95% confidence interval [CI] = 1.08-4.15; 10 deaths). Furthermore, among highly exposed women (defined by a job-exposure matrix), we found an excess of Parkinson disease (SMR-2.95; 95% CI = 1.08-6.42; 6 deaths) and dementia (SMR-2.04; 95% CI = 1.12-3.43; 14 deaths). CONCLUSIONS: Our data are limited due to small numbers and reliance on mortality rather than incidence data, but are suggestive of an effect of PCBs on neurodegenerative disease for women. The literature does not offer an explanation for why women would be more affected than men by PCB exposure for these outcomes.

Dose-Response Relationship, Drug↗

PubMed2006

Mortality among workers exposed to polychlorinated biphenyls (PCBs) in an electrical capacitor manufacturing plant in Indiana: an update.

An Indiana capacitor-manufacturing cohort (n=3,569) was exposed to polychlorinated biphenyls (PCBs) from 1957 to 1977. The original study of mortality through 1984 found excess melanoma and brain cancer; other studies of PCB-exposed individuals have found excess non-Hodgkin lymphoma and rectal, liver, biliary tract, and gallbladder cancer. Mortality was updated through 1998. Analyses have included standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) using rates for Indiana and the United States, standardized rate ratios (SRRs), and Poisson regression rate ratios (RRs). Estimated cumulative exposure calculations used a new job-exposure matrix. Mortality overall was reduced (547 deaths; SMR, 0.81; 95% CI, 0.7-0.9). Non-Hodgkin lymphoma mortality was elevated (9 deaths; SMR, 1.23; 95% CI, 0.6-2.3). Melanoma remained in excess (9 deaths; SMR, 2.43; 95% CI, 1.1-4.6), especially in the lowest tertile of estimated cumulative exposure (5 deaths; SMR, 3.72; 95% CI, 1.2-8.7). Seven of the 12 brain cancer deaths (SMR, 1.91; 95% CI, 1.0-3.3) occurred after the original study. Brain cancer mortality increased with exposure (in the highest tertile, 5 deaths; SMR, 2.71; 95% CI, 0.9-6.3); the SRR dose-response trend was significant (p=0.016). Among those working >or= 90 days, both melanoma (8 deaths; SMR, 2.66; 95% CI, 1.1-5.2) and brain cancer (11 deaths; SMR, 2.12; 95% CI, 1.1-3.8) were elevated, especially for women: melanoma, 3 deaths (SMR, 5.99; 95% CI, 1.2-17.5); brain cancer, 3 deaths (SMR, 2.87; 95% CI, 0.6-8.4). These findings of excess melanoma and brain cancer mortality confirm results of the original study. Melanoma mortality was not associated with estimated cumulative exposure. Brain cancer mortality did not demonstrate a clear dose-response relationship with estimated cumulative exposure.

Adult↗

PubMed2006

Mortality and exposure response among 14,458 electrical capacitor manufacturing workers exposed to polychlorinated biphenyls (PCBs).

BACKGROUND: We expanded an existing cohort of workers (n = 2,588) considered highly exposed to polychlorinated biphenyls (PCBs) at two capacitor manufacturing plants to include all workers with at least 90 days of potential PCB exposure during 1939-1977 (n = 14,458). Causes of death of a priori interest included liver and rectal cancers, previously reported for the original cohort, and non-Hodgkin lymphoma (NHL), melanoma, and breast, brain, intestine, stomach, and prostate cancers, based on other studies. METHODS: We ascertained vital status of the workers through 1998, and cumulative PCB exposure was estimated using a new job exposure matrix. Analyses employed standardized mortality ratios (SMRs; U.S., state, and county referents) and Poisson regression modeling. RESULTS: Mortality from NHL, melanoma, and rectal, breast, and brain cancers were neither in excess nor associated with cumulative exposure. Mortality was not elevated for liver cancer [21 deaths; SMR 0.89; 95% confidence interval (CI), 0.55-1.36], but increased with cumulative exposure (trend p-value = 0.071). Among men, stomach cancer mortality was elevated (24 deaths; SMR 1.53; 95% CI, 0.98-2.28) and increased with cumulative exposure (trend p-value = 0.039). Among women, intestinal cancer mortality was elevated (67 deaths; SMR 1.31; 95% CI, 1.02-1.66), especially in higher cumulative exposure categories, but without a clear trend. Prostate cancer mortality, which was not elevated (34 deaths; SMR 1.04; 95% CI, 0.72-1.45), increased with cumulative exposure (trend p-value = 0.0001). CONCLUSIONS: This study corroborates previous studies showing increased liver cancer mortality, but we cannot clearly associate rectal, stomach, and intestinal cancers with PCB exposure. This is the first PCB cohort showing a strong exposure-response relationship for prostate cancer mortality.

Adult↗

PubMed2005

Nicotine exposure and decontamination on tobacco harvesters' hands.

Green tobacco sickness is an illness associated with nicotine exposures among tobacco harvesters. Agricultural workers manually harvest tobacco and thus have the potential for skin exposure to nicotine, particularly on the hands. Often gloves are not worn as it hinders the harvesters' ability to harvest the tobacco leaves. The purposes of this study were to measure the concentration of nicotine residue on the hands of tobacco harvesters and the effectiveness of hand washing at removing the residue. Wipe samples from the hands of 12 tobacco harvesters were collected at the end of morning and afternoon work periods over two consecutive days. Each harvester had one hand wiped before washing his hands, and the other hand wiped after washing his hands with soap and water. Eight samples per worker were collected over the two days for a total of 96 samples collected. In addition to the hand-wipe samples, leaf-wipe samples were collected from 15 tobacco plants to estimate the amount of nicotine residue on the plants. The average nicotine level in leaf-wipe samples was 1.0 microg cm(-2). The geometric mean pre-wash and post-wash nicotine levels on the hands were 10 and 0.38 microg cm(-2), respectively. Nicotine leaf-wipe level, right or left hand and time of sampling did not significantly influence exposure. Job position-working on the bottom versus the top of the tobacco harvesting machine-was associated with nicotine levels. Pre-wash nicotine levels were higher for workers on the bottom of the harvester but not significantly higher (P = 0.17). Post-wash nicotine levels were significantly higher for workers on the bottom of the harvester (P = 0.012). A substantial amount of nicotine was transferred to the hands, but washing with soap and water in the field significantly reduced nicotine levels by an average of 96% (P < 0.0001).

Agriculture↗

PubMed2005

Urinary and hand wipe pesticide levels among farmers and nonfarmers in Iowa.

In the spring and summer of 2001, as part of a larger study investigating farm family pesticide exposure and home contamination in Iowa, urine and hand wipe samples were collected from 24 male farmers and 23 male nonfarmer controls. On two occasions approximately 1 month apart, one hand wipe sample and an evening and morning urine sample were collected from each participant. The samples were analyzed for the parent compound or metabolites of six commonly used agricultural pesticides: alachlor, atrazine, acetochlor, metolachlor, 2,4-dichlorophenoxyacetic acid (2,4-D) and chlorpyrifos. For atrazine, acetochlor, metolachlor and 2,4-D, farmers who reported applying the pesticide had significantly higher urinary metabolite levels than nonfarmers, farmers who did not apply the pesticide, and farmers who had the pesticide commercially applied (P-value <0.05). Generally, there were no differences in urinary pesticide metabolite levels between nonfarmers, farmers who did not apply the pesticide, and farmers who had the pesticide commercially applied. Among farmers who reported applying 2,4-D themselves, time since application, amount of pesticide applied, and the number of acres to which the pesticide was applied were marginally associated with 2,4-D urine levels. Among farmers who reported applying atrazine themselves, time since application and farm size were marginally associated with atrazine mercapturate urine levels. Farmers who reported using a closed cab to apply these pesticides had higher urinary pesticide metabolite levels, although the difference was not statistically significant. Farmers who reported using closed cabs tended to use more pesticides. The majority of the hand wipe samples were nondetectable. However, detection of atrazine in the hand wipes was significantly associated with urinary levels of atrazine above the median (P-value <0.01).

Agriculture↗

PubMed2005

Pesticide contamination inside farm and nonfarm homes.

Twenty-five farm (F) households and 25 nonfarm (NF) households in Iowa were enrolled in a study investigating agricultural pesticide contamination inside homes. Air, surface wipe, and dust samples were collected. Samples from 39 homes (20 F and 19 NF) were analyzed for atrazine, metolachlor, acetochlor, alachlor, and chlorpyrifos. Samples from 11 homes (5 F and 6 NF) were analyzed for glyphosate and 2,4-Dichlorophenoxyac etic acid (2,4-D). Greater than 88% of the air and greater than 74% of the wipe samples were below the limit of detection (LOD). Among the air and wipe samples, chlorpyrifos was detected most frequently in homes. In the dust samples, all the pesticides were detected in greater than 50% of the samples except acetochlor and alachlor, which were detected in less than 30% of the samples. Pesticides in dust samples were detected more often in farm homes except 2,4-D, which was detected in 100% of the farm and nonfarm home samples. The average concentration in dust was higher in farm homes versus nonfarm homes for each pesticide. Further analysis of the data was limited to those pesticides with at least 50% of the dust samples above the LOD. All farms that sprayed a pesticide had higher levels of that pesticide in dust than both farms that did not spray that pesticide and nonfarms; however, only atrazine and metolachlor were significantly higher. The adjusted geometric mean pesticide concentration in dust for farms that sprayed a particular pesticide ranged from 94 to 1300 ng/g compared with 12 to 1000 ng/g for farms that did not spray a particular pesticide, and 2.4 to 320 ng/g for nonfarms. The distributions of the pesticides throughout the various rooms sampled suggest that the strictly agricultural herbicides atrazine and metolachlor are potentially being brought into the home on the farmer's shoes and clothing. These herbicides are not applied in or around the home but they appear to be getting into the home para-occupationally. For agricultural pesticides, take-home exposure may be an important source of home contamination.

Agriculture↗

PubMed2003

Acephate exposure and decontamination on tobacco harvesters' hands.

Agricultural workers manually harvesting tobacco have the potential for high dermal fexposure to pesticides, particularly on the hands. Often gloves are not worn as it hinders the harvesters' ability to harvest the tobacco leaves. To enable harvesters to remove pesticide residue on the hands and decrease absorbed doses, the EPA Worker Protection Standard requires growers to have hand-wash stations available in the field. The purpose of this study was to measure the concentration of acephate residue on the hands of tobacco harvesters, and the effectiveness of hand washing in reducing the acephate residue. Hand-wipes from the hands of 12 tobacco harvesters were collected at the end of the morning and at the end of the afternoon over 2 consecutive days. Each harvester had one hand-wiped prior to washing his hands, and the other hand-wiped after washing his hands with soap and water. In addition to the hand-wipe samples, leaf-wipe samples were collected from 15 tobacco plants to determine the amount of acephate residue on the plants. The average acephate level in leaf-wipe samples was 1.4 ng/cm(2). The geometric mean prewash and postwash acephate levels on the hands were 10.5 and 0.4 ng/cm(2), respectively. Both prewash (P-value=0.0009) and postwash hand (P-value=0.01) samples were positively correlated with leaf-wipe concentrations. Tobacco harvester position tended to influence hand exposure. Hand washing significantly reduced acephate levels on the hand, after adjusting for sampling period, hand sampled, job position, and leaf-wipe concentration (P-value< or =0.0001) with levels reduced by 96%. A substantial amount of acephate was transferred to the hands, and while hand washing significantly reduced the amount of residue on the hands, not all residue was removed.

Agriculture↗

PubMed2003

Measuring and identifying large-study metrics for circadian rhythm disruption in female flight attendants.

OBJECTIVES: Flight attendants can experience circadian rhythm disruption due to travel through multiple time zones. The objectives of this study were to determine whether flight attendants are more likely than teachers (comparison group) to experience circadian disruption, as measured by melatonin production, and to identify metrics of circadian disruption for epidemiologic studies of reproductive health in which biomonitoring is infeasible. METHODS: Each day, for one menstrual cycle, 45 flight attendants and 26 teachers kept a daily diary, collected and measured their overnight urine, and wore an activity monitor to assess sleep displacement. The relation between melatonin production and flight attendant and teacher status was analyzed with linear and multiple logistic regression. The relation between sleep displacement, melatonin, and flight-history-derived variables (including time zones crossed) were examined with exploratory factor analyses. RESULTS: Flight attendants experience increased circadian disruption, as measured by a higher adjusted melatonin rate variance, than teachers [2.8 x 10(5) versus 1.0 x 10(5) (ng/hour)2, respectively: P=0.04] and are more likely to be in the highest quartile of melatonin variance (odds ratio 2.3; 95% confidence interval 0.6-9.1). In the factor analysis, the number of time zones crossed was related to both melatonin desynchronization and sleep displacement. CONCLUSIONS: Flight attendants experience increased circadian disruption, as measured by more variable melatonin rates, than a minimally flying comparison group. For epidemiologic studies of flight crews in which melatonin measurement is infeasible, the number of time zones crossed is a useful indicator of both sleep displacement and melatonin desynchronization.

Adolescent↗

PubMed2002

Surface sampling methods for Bacillus anthracis spore contamination.

During an investigation conducted December 17-20, 2001, we collected environmental samples from a U.S. postal facility in Washington, D.C., known to be extensively contaminated with Bacillus anthracis spores. Because methods for collecting and analyzing B. anthracis spores have not yet been validated, our objective was to compare the relative effectiveness of sampling methods used for collecting spores from contaminated surfaces. Comparison of wipe, wet and dry swab, and HEPA vacuum sock samples on nonporous surfaces indicated good agreement between results with HEPA vacuum and wipe samples. However, results from HEPA vacuum sock and wipe samples agreed poorly with the swab samples. Dry swabs failed to detect spores >75% of the time when they were detected by wipe and HEPA vacuum samples. Wipe samples collected after HEPA vacuum samples and HEPA vacuum samples collected after wipe samples indicated that neither method completely removed spores from the sampled surfaces.

Bacillus anthracis↗