A critical review of developmental exposure to particulate matter, autism spectrum disorder, and attention deficit hyperactivity disorder.

Autism spectrum disorder (ASD) and attention deficit (hyperactivity) disorder (ADD/ADHD) are key focuses of current health research due to their increasing prevalence. The objective of this systematic literature search and critical review was to evaluate whether the human epidemiologic data indicate a pattern of association between ASD or ADD/ADHD and developmental exposure to particulate matter (PM), with a focus on exposures encountered before the age of three. A MEDLINE and EMBASE search was conducted; following preliminary and full-text screening, 14 relevant articles were identified for review. Three of the 14 studies were prospective cohort studies evaluating exposure to PM10; 11 studies had a case-control design. There was no consistent association between developmental PM exposure and ASD across the three of the cohort studies. Seven of the case-control studies examined the relationship between PM2.5 and/or PM10 and ASD; four examined the relationship between developmental diesel PM exposure and ASD. Overall, there was low external consistency in results among studies of PM2.5/PM10 and ASD, with some reporting high internal consistency without significant associations, others showing associations with high internal consistency for specific exposure windows only (e.g., third trimester), and still others showing high consistency for moderate to strong associations between PM and ASD. The majority of studies reporting significant results had low effect sizes in conjunction with small sample sizes. The four studies of diesel PM and ASD also had low external consistency of results. Only one study evaluated associations with ADD/ADHD, and it found no significant associations with PM10. The inconsistent findings across studies of developmental exposure to PM and ASD may be attributed to differences in the study populations, exposure assessments, outcome assessments, or chance. Further research is needed to understand the underlying biological mechanisms that lead to ASD and ADD/ADHD and how PM might be involved in those mechanisms, if at all. High-quality epidemiologic studies are also needed to conclusively determine whether developmental PM exposure is a causal factor for ASD or ADD/ADHD, with focus on a well-developed exposure assessment.

An analysis of fatal and non-fatal injuries and injury severity factors among electric power industry workers.

BACKGROUND: The electric power industry represents a unique subset of the U.S. workforce. We aimed to evaluate the relationships between occupational category, nature of injury, and injury severity among electric power industry workers. METHODS: The Occupational Health and Safety Database (1995-2013) was used to calculate injury rates, assess patterns of injury severity, and identify at-risk occupations in this population. RESULTS: Over the surveillance period, a total of 63,193 injuries were reported. Overall, and severe injury rates were 3.20 and 0.52 per 100 employee-years, respectively. The fatal injury rate was 3.29 per 100,000 employee-years. Line workers experienced the highest risk for fatal injuries and second highest for non-fatal severe injuries, following meter readers. The most severe non-fatal injuries were hernia and rupture; multiple injuries; and CTD/RSI. Fatal injuries were most commonly associated with vehicle collisions and contact with electric current. CONCLUSIONS: Industry specific surveillance and interventions tailored to high-risk occupations are needed to further reduce severe injuries in this population. Am. J. Ind. Med. 59:948-958, 2016. © 2016 Wiley Periodicals, Inc.

Factors that distinguish serious versus less severe strain and sprain injuries: an analysis of electric utility workers.

BACKGROUND: Occupational sprain and strain injuries are one of the most common types of nonfatal occupational injuries and a significant source of lost workdays. This study examines factors associated with severe work-related sprain/strain injuries to the back, shoulder, and knees. METHODS: A synthetic case-control study was performed (controls were selected from the same pool of utility workers as cases). Cases included all electric utility workers who had experienced a severe work-related sprain/strain injury to the back, knee, or shoulder. Primary controls were selected from all workers who had sustained a minor injury. Secondary controls were selected from employees with a minor sprain/strain injury to the back, knee, or shoulder. Multivariate logistic regression models were used to estimate odds ratios and 95% confidence intervals. RESULTS: Workers 41 years and older were more likely to have experienced severe shoulder sprain/strain injuries [Age 41-50: OR = 3.62, 95% CI: 1.71-7.65; age 51 and older: OR = 4.49, 95% CI: 1.89-10.67] and severe back sprain/strain injuries [Age 41-50: OR = 1.70, 95% CI: 1.06-2.33; age 51 and older: OR = 1.5, 95% CI: 0.90-2.52]. Line workers and maintenance workers had an increased risk of serious sprain/strain injuries. Gender and day of week were not significantly associated with sprain/strain injuries. DISCUSSION: Though this study is limited by available data, future studies may benefit from this preliminary examination of occupational and demographic characteristics associated with serious sprain/strain injuries among electric utility workers.

An integrated job exposure matrix for electrical exposures of utility workers.

Electric utility workers may be exposed to any combination of magnetic fields, electric fields, nuisance shocks (from spark discharges and continuous currents), imperceptible contact currents, and electrical injuries. Collectively these exposures are referred to as EMF Factors. Previous occupational exposure assessments have mainly characterized the magnetic field, with less attention to the electric field. Nuisance shocks and electrical injuries, though palpable, have received little to no attention. This article presents a prototype job exposure matrix that addresses exposure to all EMF Factors taking into account job category, work environment, and occupied environment. Exposures for all factors were classified into three ordinal levels for 22 job categories. Electric and magnetic field exposures were classified by the geometric mean of daily average of personal exposure measurements. Although relatively sparse, survey data on nuisance shocks were adequate for exposure assignment by job category and indicate that the frequency of these exposures has diminished over time. The least information was available for imperceptible contact currents that are associated with electric field exposures and small contact voltages. Data for electrical injuries by job category were derived from the Electric Power Research Institute Occupational Health Surveillance Database, with exposure assignments based on combined injury rates for flash burn and electric shock/electrocution. The highest exposures for all EMF Factors are essentially limited to four job categories that work on or close to electrical equipment: (1) cable splicers, (2) electricians, (3) line workers, and (4) substation operators.

A 37-year Update on Mortality Patterns in an Expanded Cohort of Vermont Talc Miners and Millers.

OBJECTIVES: The aim of this study was to update a cohort of Vermont talc workers to include 37 additional years of follow-up time. METHODS: Standardized mortality ratios (SMR) and 95% confidence intervals (CIs) were calculated for 70+ causes of death. US population mortality rates were used as reference. RESULTS: All-cause mortality was 30% higher than the US population (SMR 133.4, 95% CI, 119.7 to 148.3). Significant elevations occurred in nonmalignant respiratory disease (NMRD) (SMR 273.0, 95% CI, 210.2 to 348.6) and other nonmalignant respiratory disease (ONMRD) (SMR 413.1, 95% CI, 287.7 to 574.5). ONMRD was elevated across all length of employment categories and a test for linear trend was significant (P = 0.007). CONCLUSIONS: This study provides further evidence that excess deaths among Vermont talc workers are due largely to excess mortality from NMRD; there is no evidence of increased risk of respiratory cancer.

Thermal burn and electrical injuries among electric utility workers, 1995-2004.

This study describes the occurrence of work-related injuries from thermal-, electrical- and chemical-burns among electric utility workers. We describe injury trends by occupation, body part injured, age, sex, and circumstances surrounding the injury. This analysis includes all thermal, electric, and chemical injuries included in the Electric Power Research Institute (EPRI) Occupational Health and Safety Database (OHSD). There were a total of 872 thermal burn and electric shock injuries representing 3.7% of all injuries, but accounting for nearly 13% of all medical claim costs, second only to the medical costs associated with sprain- and strain-related injuries (38% of all injuries). The majority of burns involved less than 1 day off of work. The head, hands, and other upper extremities were the body parts most frequently injured by burns or electric shocks. For this industry, electric-related burns accounted for the largest percentage of burn injuries, 399 injuries (45.8%), followed by thermal/heat burns, 345 injuries (39.6%), and chemical burns, 51 injuries (5.8%). These injuries also represented a disproportionate number of fatalities; of the 24 deaths recorded in the database, contact with electric current or with temperature extremes was the source of seven of the fatalities. High-risk occupations included welders, line workers, electricians, meter readers, mechanics, maintenance workers, and plant and equipment operators.

A mortality study of beryllium workers.

We aimed at investigating mortality among beryllium-exposed workers, according to solubility of beryllium and beryllium compounds. We conducted an historical cohort study of 16,115 workers employed during 1925-2008 in 15 facilities, including eight entailing exposure to insoluble beryllium and seven entailing exposure to soluble/mixed beryllium compounds, who were followed up for mortality until 2011. Data were analyzed using indirect standardization and Cox regression modeling. Lung cancer standardized mortality ratio (SMR, national reference rates) was 1.02 (95% confidence interval [CI]: 0.94-1.10) in the whole cohort, 0.88 (95% CI: 0.75-1.03) in the insoluble beryllium subcohort, and 1.09 (95% CI: 0.99-1.09) in the soluble/mixed beryllium subcohort. For lung cancer, there was an association with period of hire in soluble/mixed beryllium plants but not in insoluble plants, and, conversely, employment in soluble/mixed plants was associated with increased mortality only among workers hired before 1955. There was no trend with duration of employment. Mortality from chronic beryllium disease increased, in particular, among workers hired before 1955 in soluble/mixed beryllium facilities. There was no increase in lung cancer mortality in the entire cohort and lung cancer mortality was not increased among beryllium workers hired in 1955 or later in soluble/mixed beryllium facilities, or at any time among those employed in insoluble beryllium facilities.

The effects of standard enforcement on Michigan safety belt use.

The purpose of this study was to assess the effects of standard enforcement legislation on safety belt use in Michigan through a series of seven statewide direct observation surveys. A secondary purpose of the study was to compare the results in Michigan to the results in other states that have changed the provision of their mandatory safety belt use law from secondary to standard enforcement. The study found that standard enforcement has been effective in increasing safety belt use in Michigan. Immediately following the implementation of standard enforcement, Michigan's belt use rate increased to 83.5%, 13.4 percentage points higher than the highest rate previously observed. One year after the change, safety belt use in Michigan was still nearly 10 percentage points greater than the highest observed rate before standard enforcement legislation was enacted. Results indicated that safety belt use decreased slightly in the year following the implementation of standard enforcement. This appears to be an overall trend across all observed groups, and not due to any single demographic category. The results also suggest that standard enforcement legislation appears to have a greater effect on groups with historically low belt use, such as young people, males, passengers, and Black/African-Americans. When compared with other states that have made the change from secondary to standard enforcement, the increase in the safety belt use rate in Michigan was comparable to the increase seen in states with relatively high safety belt use prior to standard enforcement. However, states that had low safety belt use rates prior to adopting standard enforcement legislation observed a larger percentage point increase in the year following their change to standard enforcement.

A comparison of safety belt use between commercial and noncommercial light-vehicle occupants.

The purpose of this study was to conduct an observational survey of safety belt use to determine the use rate of commercial versus noncommercial light-vehicle occupants. Observations were conducted on front-outboard vehicle occupants in eligible commercial and noncommercial vehicles in Michigan (i.e.. passenger cars, vans/minivans, sport-utility vehicles, and pickup trucks). Commercial vehicles that did not fit into one of the four vehicle type categories, such as tractor-trailers, buses, or heavy trucks, were not included in the survey. The study found that the restraint use rate for commercial light-vehicle occupants was 55.8% statewide. The statewide safety belt use rate for commercial light-vehicles was significantly lower than the rate of 71.2% for noncommercial light-vehicles. The safety belt use rate for commercial vehicles was also significantly different as a function of region, vehicle type, seating position, age group, and road type. The results provide important preliminary data about safety belt use in commercial versus noncommercial light-vehicles and indicate that further effort is needed to promote safety belt use in the commercial light-vehicle occupant population. The study also suggests that additional research is required in order to develop effective programs that address low safety belt use in the commercial light-vehicle occupant population.

Improving older driver knowledge and self-awareness through self-assessment: the driving decisions workbook.

PURPOSE: This study aims to assess whether the Driving Decisions Workbook, a self-assessment instrument for older drivers, increased self-awareness and general knowledge. This study also assessed perceptions regarding its usefulness, particularly as a tool for facilitating discussions within families of older drivers. A secondary purpose of the study was to determine if problems identified by drivers in the workbook related to problems they had with actual driving. DESIGN AND METHODS: The Driving Decisions Workbook was administered along with a questionnaire and a road test. A convenience sample of 99 licensed drivers aged 65 and above was used. RESULTS: After completing the workbook, about three fourths of the participants reported being more aware of changes that could affect driving. Fourteen percent reported that they had discovered a change in themselves of which they had not been previously aware. All respondents found the workbook to be at least a little useful and thought the workbook could help facilitate family discussions. Workbook responses were positively correlated with overall road test scores. Significant correlations were also noted between the road test and a majority of workbook subsection responses. IMPLICATIONS: This study indicates that the workbook may be a useful first-tier assessment instrument and educational tool for the older driver. It may encourage an older driver to drive more safely and/or to seek clinical assessment, and help in facilitating discussions about driving within their families.

Neck injuries among electric utility workers, 1995-2007.

OBJECTIVE: To describe the incidence and impact of neck injuries among electric utility workers. METHODS: Rates of neck injuries per 10,000 employee-years were calculated for various demographic and occupational factors using data from an injury surveillance database established among 17 electric utility companies over the period 1995-2007. RESULTS: The overall rate of neck injuries was 13.3. Male workers had a slightly higher rate than females, and younger workers (<30) had the highest neck injury rates. Trade/craft workers experienced the highest rates of neck injuries, whereas office-based experienced the lowest. The majority of neck injuries (69%) were sprain/strains and resulted in less than 1 lost day of work (76.7%). CONCLUSIONS: The occurrence of neck injuries in the electric utility workforce varies widely with respect to age, sex, and occupational groups with different characteristics, activities, and work environments. Industry-wide surveillance allows easier identification of injury patterns and risk factors of various injury types and facilitates the development of targeted prevention and intervention strategies to reduce the occurrence of these injuries.