Research conducted by LSU Health New Orleans School of Public Health finds that the current recommendations for running water to flush out lead are not consistently effective and may not be the best way to protect children from lead in drinking water. The findings are published in the International Journal of Environmental Research and Public Health available online here.

“While flushing taps according to prevailing guidelines (for 30 seconds to 2 minutes) may reduce water lead levels for some homes, over half the tested homes had peak water lead levels after that time, so these recommendations may inadvertently increase exposures,” notes study leader Adrienne Katner, DEnv, Assistant Research Professor of Environmental & Occupational Health Sciences at LSU Health New Orleans School of Public Health. “More effective interventions like certified water filters should be considered instead, particularly when replacing water service lines and plumbing is not economically possible.”

The research team surveyed homeowners and tested water samples from 376 New Orleans homes on the East Bank of the Mississippi River (the city’s water source) between February 2015 and November 2016. Recruited homes met criteria for the potential presence of lead. Virginia Tech colleagues analyzed the water samples, which were first cold water draws, first hot water draws, draws after letting the water run for 30 – 45 seconds, 2.5 – 3 minutes or 5.5 – 6 minutes.

Overall, New Orleans water lead levels were typically low compared to the EPA’s action level of 15 ppb. The analysis revealed a water lead level of 5 ppb in 88% of all samples from normal-use residential sites. More than half of all samples from normal use sites (60%) had detectable water lead levels of at least 1 ppb or higher. Water lead levels ranged from non-detectable (less than 1 ppb) to 58 ppb found in samples after flushing for 30-45 seconds. There was no significant difference in water lead level distribution after flushing for the various amounts of time until the six-minute mark after which the water lead level distribution decreased.

“While the percent of samples with water lead levels exceeding 1 ppb did decrease after extended flushing for 5.5 to 6 min, the reductions were not always substantial,” says Dr. Katner. “If the aim is to prevent childhood lead exposure altogether, preferably, or at least reduce it to the minimally detectable level (1 ppb) as recommended by the American Academy of Pediatricians, then New Orleans may require more proactive interventions than flushing to meet this goal. We could not verify that a one-time flush is sufficient to maintain low water lead levels. Some studies evaluating flushing at school taps suggest frequent flushes may be needed throughout the day, as waterborne lead can return to pre-flush levels within hours. Prolonged and repeated flushing may also not be practical, cost-effective, or sustainable over the long term, especially in cities with declining water resources and/or rising water rates.”

Katner and her colleagues conclude, “Public health messages should be modified to ensure appropriate application of flushing, while acknowledging its short-comings and practical limitations.”

In addition to Katner, the LSU Health New Orleans research team included Drs. Hui-Yi Lin, Chih-Yang Hu, as well as Komal Brown and Xinnan Wang. Researchers from Virginia Tech, Tulane University, and Corona Environmental Consulting also participated.The research was supported in part by the Louisiana Board of Regents’ New Research Pilot Funding Program, the National Science Foundation, LSU Health New Orleans School of Public Health and the National Institutes of Health.

Source

Faculty and researchers at the LSU School of Medicine (Drs. Stephen Kantrow and Sarah Jolley), Louisiana State University Health Sciences Center School of Public Health (Ms. Xinnan Wang, Dr. Tung-Sung Tseng, Dr. Dodie Arnold, Dr. Claudia Leonardi, Dr. Richard Scribner, Dr. Edward Trapido, Dr. Hui-Yi Lin), Ochsner Health System (Eboni Price Haywood) and the Louisiana Public Health Institute (Dr. Lisanne Brown) used emergency department (ED) data to estimate the prevalence of smoking in young adults. Most state or national surveys of smoking are limited in size- especially when looking at county level data, and phone based surveys have had decreasing responses. School based surveys are helpful, but limited by age.

The researchers used data from electronic health records (EHRs) for five EDs within U.S. Census-defined metropolitan New Orleans (New Orleans–Metairie, LA) for persons 18-24 years old. (15 percent of young adults are reported to have used EDs in the past year). Smoking status was available for 55,777 persons (91 percent of the total Emergency Departments); 61 percent were women, 55 percent were black, 35 percent were white, and 8 percent were Hispanic. One third of patients were uninsured. Most smokers used cigarettes (95 percent ). Prevalence of current smoking was 21.7 percent for women and 42.5 percent for men. Smoking prevalence was highest for substance use disorder (58 percent ), psychiatric illness (41 percent ) and alcohol use (39 percent ), and lowest for pregnancy (13.5 percent ). In multivariable analyses, male gender, white race, lack of health insurance, alcohol use, and illicit drug use were independently associated with smoking. Smoking risk among alcohol and drug users varied by gender, race, and/or age.

The BRFSS estimated 29 percent prevalence during the same time, and had data on 597 subjects aged 18–30 years. Although ED data are likely to overestimate tobacco use, the large sample size is useful- especially for stratum-specific estimates- particularly in a demographically diverse population. Dr. Stephen Kantrow, the lead investigator, stated ”this approach provides smoking data for a large sample of young adults in one metropolitan area, and may support longitudinal studies of smoking in high and low risk populations.

Full article

BY LESLIE CAPO
(504) 568-4806; CELL (504) 452-9166

New Orleans, LA – Research led by Hui-Yi Lin, PhD, Associate Professor of Biostatistics at  LSU Health New Orleans School of Public Health, has developed another novel statistical method for evaluating gene-to-gene interactions associated with cancer and other complex diseases. The Additive-Additive 9 Interaction (AA9int) method is described in a paper published in Bioinformatics, available online here.

“This method can identify combinations of genetic variants for predicting cancer risk and prognosis,” notes Dr. Lin, who is also the paper’s lead author.

AA9int is based upon another method Lin developed, SNP Interaction Pattern Identifier (SIPI), to identify interactions between single nucleotide polymorphisms (SNPs). According to the National Institutes of Health, “Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide.  Most commonly, these variations are found in the DNA between genes. They can act as biological markers, helping scientists locate genes that are associated with disease. When SNPs occur within a gene or in a regulatory region near a gene, they may play a more direct role in disease by affecting the gene’s function.”

Although SNP-SNP or gene-gene interaction studies have been emerging, the statistical methods for evaluating SNP-SNP interactions are still in their infancy. The conventional approach to test SNP interactions is to use a hierarchical interaction model with two main effects plus their interaction with both SNPs as an additive inheritance mode. However, this approach tests just one specific type of interaction, which can lead to many false negative findings.

SNP Interaction Pattern Identifier (SIPI), the first statistical method to thoroughly search for meaningful SNP-SNP interaction patterns in cancer and other complex diseases, can detect novel SNP interactions that the conventional statistical approach cannot. SIPI evaluates 45 SNP interaction patterns. Its computational demands are large, however, which may not be desirable for large-scale studies. So, Lin and her colleagues sought a smaller version with fewer testing models but with similar power. They showed that a mini version of SIPI – AA9int, which is composed of nine interaction models – used only about 20% of computing time. More efficient and feasible for large-scale studies, AA9int is still more effective than the traditional approach.

“We found that AA9int successfully detected 72-90% of the SIPI-identified SNP pairs,” reports Lin. “Not meant to replace SIPI, but for large-scale studies, AA9int is a powerful tool that can be used alone or as the screening stage of a two-stage approach (AA9int+SIPI) to detect SNP-SNP interactions.”

The research team also studied the impact of inheritance mode and model structure on detecting SNP-SNP interactions. SNP Interaction Pattern Identifier (SIPI) evaluates SNP interaction patterns by considering three major factors: model structure (hierarchical and non- hierarchical model), genetic inheritance mode (dominant, recessive and additive), and mode coding direction. AA9int considers non-hierarchical model structure and the additive mode. They found that non-hierarchical models play a more important role in SNP interaction detection than inheritance modes.

“These identified gene-gene or SNP-SNP interactions increase our understanding of the biological mechanisms of cancer development and may improve cancer diagnosis accuracy and reduce cancer-related deaths in the future.” Lin concludes.

The research team included scientists from the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) Consortium.

Computational facilities at LSU Health New Orleans School of Public Health were supported by high-performance computational resources provided by the Louisiana Optical Network Infrastructure (LONI).

The research was supported by a grant from the National Cancer Institute of the National Institutes of Health.

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13th Annual Public Health Finance Roundtable
Sunday, November 5th, 2017 Georgia World Congress Center – Room A405 3:00pm to 5:30pm
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APHA Film Festival: Screening of LSU Sponsored film “Michelle’s Story”
Session FF12: Global Public Health Film Festival: Inform, Educate, Empower, session 4 scheduled for Tuesday, November 7, 2017: 6:30 p.m.-8:00 p.m. 

Individual Presentations:

• Oral Presentation
  “Expanding Patient Navigation Services in the Louisiana Breast and Cervical Health Program”
  Courtney S. Wheeler, MPH, Nannozi Ssenkoloto, MPH, Joann Lee, MPH, Donna Williams, DrPH
• Poster Presentation
  “Drowned Out: The Smoke-Free East Baton Rouge Campaign and the Impact of a Thousand Year Flood”
  Authors: Aubree Thelen, MPH, Mikal Giancola, MPH, Lydia Kuykendal, MPH, Tonia Moore
• Poster Presentation
  “Gender And Age Disparities In Relationship Of Acculturation, Sugar-sweetened Beverages Consumption And Obesity Among Latino Immigrants”
  Authors: Tung-Sung Tseng, DrPH, Shuang Yang, MS, Daesy K. Behrhorst, BA , Yu-Wen Chiu, DrPH, Chih-Yang Hu, MSPH, ScD , Hui-Yi Lin, PhD