American Journal of Public Health highlights:

1. Repeal of Michigan motorcycle helmet law leads to decreased helmet use, increased head injuries2. Predominantly black neighborhoods in Wake County, North Carolina, have higher exposure to contaminated drinking water3. People living in poorest U.S. counties have shorter life expectancy than majority of world countries

Note: Hyperlinks to the studies will go live following the embargo lift on Nov. 17, 2016, at 4 p.m. EST.

Newswise — Repeal of Michigan motorcycle helmet law leads to decreased helmet use, increased head injuries

The 2012 partial repeal of Michigan’s universal motorcycle helmet law resulted in less helmet use and more head injuries, according to a new study in the American Journal of Public Health.

Researchers compared helmet use rates and motorcycle crash fatality risk for the 12 months before and after the law repeal by using a statewide data set of police-reported crashes. They linked police-reported crashes to injured riders in a statewide trauma registry, and compared head injury before and after the repeal.

Results showed that after the repeal, helmet use decreased by 24 percent in crash samples and 27 percent in trauma samples. Head injuries among hospitalized motorcyclists increased by 14 percent. Male gender, alcohol intoxication, intersection crashes and crashes at higher speed limits increased fatality risk. Not wearing a helmet and alcohol intoxication increased head injury odds. Fatality rate overall, however, did not change.

“Michigan’s partial universal motorcycle helmet law repeal decreased helmet use and increased head injury among crash-involved motorcyclists. Furthermore, helmet non-use doubled the odds of a fatality and tripled the odds of a head injury,” the authors explain. “Future research should examine the impact of Michigan’s helmet repeal by using additional years of data as they become available and examine the underlying direct and indirect costs associated with the repeal, especially the societal costs associated with providing more long-term head injury care for patients involved in motorcycle crashes.”

[“The Impact of Michigan’s Partial Repeal of the Universal Motorcycle Helmet Law on Helmet Use, Fatalities and Health Injuries.” Contact: Patrick M. Carter, MD, University of Michigan Injury Center, University of Michigan School of Medicine, Ann Arbor, Michigan.]

Predominantly black neighborhoods in Wake County, North Carolina, have higher exposure to contaminated drinking water

According to a new study in the American Journal of Public Health, predominantly black neighborhoods excluded from municipal water service have poorer quality drinking water than nearby neighborhoods with access to municipal services.

Based on census data, researchers recruited households from majority black neighborhoods in Wake County, North Carolina, that lack access to municipal water service. They tested three water samples collected July-December 2014 in 57 private wells from these neighborhoods for microbial contaminants. They compared contaminant prevalence in the wells to those in adjacent community water systems. They also assessed the number of annual emergency department visits for acute gastrointestinal illness.

Results showed that overall, 29 percent of private well samples tested positive for total coliform bacteria and 6.4 percent tested positive for E. coli – two organisms used as indicators of fecal contamination. In comparison, municipal water system samples tested positive for 0.6 percent and 0.01 percent of each bacteria type, respectively. Further, researchers estimate that 22 percent of 114 annual emergency department visits could be prevented by extending community water service.

“Our study results suggest that the lack of support for private well owners to test and maintain their wells has left underbounded communities at much greater risk of exposure to fecal contaminants in their drinking water and at increased health risk compared with adjacent communities connected to community water systems,” the authors explain. “In addition to the potential economic burden of maintaining aging private wells and septic systems, increased health risks impose costs on the affected households. Extending public infrastructure is one way to eliminate the current disparity in water quality and health risk among underbounded communities”

[“Exposure to Contaminated Drinking Water and Health Disparities in North Carolina.” Contact: Jacqueline MacDonald Gibson, PhD, Department of Environmental Science and Engineering, University of North Carolina, Chapel Hill, North Carolina.]

People living in poorest U.S. counties have shorter life expectancy than majority of world countries

People living in America’s poorest counties have shorter life expectancy than populations of more than half the countries in the world, as well as significant health disparities compared to those living in the wealthiest U.S. counties, according to new research in the American Journal of Public Health.

Researchers from East Tennessee State University reclassified the 3,141 counties in the U.S. into 50 new “states,” using the socioeconomic status indicator of five-year average median household income. The two percent of U.S. counties with the lowest household income made up the poorest “state,” followed by the next two percent of poorest counties, and so on, concluding with the two percent of counties with the highest median household income making up the wealthiest “state.” Each “state” included 62 or 63 counties. Then, using the County Health Rankings National data and other data sources, they compared differences in measures of health and well-being among the poorest and wealthiest “states.”

Results showed significant differences in almost every measure of health and well-being between America’s wealthiest and poorest “states,” including life expectancy and smoking and obesity rates. Specifically, average life expectancy was higher for residents of wealthiest “states” compared to poorest “states” — seven more years for women and nearly 10 for men. Adults in the poorest “state” had double the smoking prevalence of those in the wealthiest “state,” and were more than 50 percent more likely to be obese and physically inactive. Results also showed that the populations of more than half the countries of the world have a longer life expectancy than Americans living in the poorest “state.”

“We believe that creating 50 new “states” — organized by median household income, instead of geographic locality — provides a highly effective mechanism to help public health workers and, more importantly, policymakers and the general public both understand and communicate the impact of poverty on health in the U.S.,” the authors explain. “This study should remind all persons living in the U.S. that poverty has a remarkable effect on health, and that this impact is found across the country, not just in those states normally thought of as being “poor.” It should also remind policymakers that efforts to improve health will be dependent, in large part, on efforts to address economic inequality.”

[“Health and Social Conditions of the Poorest Versus Wealthiest Counties in the United States.” Contact: Randy Wykoff, MD, College of Public Health, East Tennessee State University, Johnson City, Tennessee.]

Find a full list of research papers to be published online on Nov. 17, 2016, at 4 p.m. EST below:• Parental Refusal of Childhood Vaccines and Medical Neglect Laws• Effectiveness of Local Policy Efforts to Increase the Price of Cheap Cigars in Minnesota• Effects of a New State Policy on Physical Activity Practices in Child Care Centers in South Carolina• Further Decline of Trans Fatty Acids Levels Among US Adults Between 1999–2000 and 2009–2010• Exposure to Contaminated Drinking Water and Health Disparities in North Carolina• Trends in Personal Belief Exemption Rates Among Alternative Private Schools: Waldorf, Montessori, and Holistic Kindergartens in California, 2000–2014• Maternal Age at Childbirth and Parity as Predictors of Longevity Among Women in the United States: The Women’s Health Initiative• Gain in Insurance Coverage and Residual Uninsurance Under the Affordable Care Act: Texas, 2013–2016• Youth Exposure to Alcohol Advertising in National Magazines in the United States, 2001–2011• Health and Social Conditions of the Poorest Versus Wealthiest Counties in the United States• Creating a Taxonomy of Local Boards of Health Based on Local Health Departments’ Perspectives• The Relationship Between US Military Officer Leadership Behaviors and Risk of Sexual Assault of Reserve, National Guard, and Active Component Servicewomen in Nondeployed Locations• Breast and Cervical Cancer Screening Literacy Among Korean American Women: A Community Health Worker–Led Intervention• The Impact of Michigan’s Partial Repeal of the Universal Motorcycle Helmet Law on Helmet Use, Fatalities and Health Injuries• Evaluation of the Acceptance Journeys Social Marketing Campaign to Reduce Homophobia

The articles above will be published online Nov. 17, 2016, at 4 p.m. EST by the American Journal of Public Health under “First Look.” “First Look” articles have undergone peer review, copyediting and approval by authors but have not yet been printed to paper or posted online by issue. The American Journal of Public Health is published by the American Public Health Association, and is available at www.ajph.org.

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