Loma Linda University

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Ryan Sinclair, PhD, MPH
Assistant Professor, School of Public Health
School of Public Health
Publications    Book Review - Scholarly Journals--Published
  • Sinclair, R. Wastewater Irrigation and Health: Assessing and Mitigating Risk in Low- Income Countries. International Journal of Water Resources Development, 2010. 26: 4, 704-709


    ( 12/2010 - 1/2011 )
  Scholarly Journals--Published
  • Pepper, I.; Brooks, J.; Sinclair, R.; Gurian, P.; and Gerba, C. Pathogens and indicators in United States class B Biosolids: National and Historic Distributions. Journal of Environmental Quality. 2010. 39(6): 2185-2190.


    ( 10/2011 )
  • Sinclair, R.; Gerba, C. Microbial contamination in kitchens and bathrooms of rural Cambodian village households. Letters in Applied Microbiology, 2011, 52(2): 144-149.


    ( 10/2011 )
  • Williams, D; Gerba, P; Maxwell, S,;Sinclair, R. Assessment of the Potential for Cross-contamination of Food Products by Reusable Shopping Bags. Food protection trends, 2011, 31(8): 508-513.


    ( 8/2011 ) Link...

    The purpose of this study was to assess the potential for cross-contamination of food products by reusable bags used to carry groceries. Reusable bags were collected at random from consumers as they entered grocery stores in California and Arizona. In interviews, it was found that reusable bags are seldom if ever washed and often used for multiple purposes. Large numbers of bacteria were found in almost all bags and coliform bacteria in half. Escherichia coli were identified in 8% of the bags, as well as a wide range of enteric bacteria, including several opportunistic pathogens. When meat juices were added to bags and stored in the trunks of cars for two hours, the number of bacteria increased 10-fold, indicating the potential for bacterial growth in the bags. Hand or machine washing was found to reduce the bacteria in bags by > 99.9%. These results indicate that reusable bags, if not properly washed on a regular basis, can play a role in the cross-contamination of foods. It is recommended that the public be educated about the proper care of reusable bags by means of printed instructions on the bags or through public service announcements.

  • Miles, S.; Sinclair, R.; Riley, M.; and Pepper, I. Evaluation of Select Sensors for Real-Time Monitoring of Escherichia coli in Water Distribution Systems. Applied and Environmental Microbiology, 2011. 77(8):2813-2816.


    ( 5/2011 )
  •  Sinclair, R.; Jones, E.; Gerba, C. Viruses in recreational waterborne disease outbreaks: A review. Journal of Applied Microbiology. 2009. 107(6): 1769-1780. ( 3/2009 - 11/2009 )
  • Sinclair, R.; Choi, C.; Romero, P.; Gerba, C. Assessment of MS-2 phage and salt tracers to characterize axial dispersion in water distribution systems. Journal of Environmental Science and Health, Part A. 2009, 44(10): 963-971. ( 1/2009 )
  • Yoon, J.; Han, J.; Choi C.; Bui M.; Sinclair R. Real-time detection of Escherichia coli in water pipe using a microfluidic device with one-step latex immunoagglutination assay.  Transactions of the ASABE. 2009, 52(3):1031-1039.

    ( 1/2009 )
  • Pepper, I.; Brooks, J.; Sinclair, R.; Gurian, P.; and Gerba, C. Pathogens and indicators in United States class B Biosolids: National and Historic Distributions. Journal of Environmental Quality. 2010. Manuscript Number Q10-0037. Accepted for publication. ( 1/2009 )
  •  Sinclair, R.; Boone, S. A.; Greenberg, D.; Keim, P.; Gerba, C. P., Persistence of Category A Select Agents in the Environment.  Applied and Environmental Microbiology 2008, 74:555-563. ( 11/2008 )
  •  Sinclair, R.; Choi, C.; Riley, M.; Gerba, C.  Pathogen surveillance through monitoring of sewer systems.  Advances in Applied Microbiology. 2008, 65:249-269. ( 6/2008 )
  •  Yel, D.; Hallen, G. K.; Sinclair, R. G.; Mom, K.; Srey, C. T., Biochemical validation of self reported quit rates among Buddhist monks in Cambodia. Tobacco Control 2005, 14:359-359. ( 6/2005 )
  •  Jeng, H. C.; Sinclair, R.; Daniels, R.; Englande, A. J., Survival of Enterococci faecalis in estuarine sediments. International Journal of Environmental Studies 2005, 62(3): 283-291. ( 6/2005 )
  • Lopez Jaime R, Somsamouth Khamphithoune, Mounivong Boualoy, Sinclair Ryan, Soret Sam, Knutsen Synnove, & Singh Pramil N. (2014). ENVIRONMENTAL EXPOSURES, LUNG FUNCTION, AND RESPIRATORY HEALTH IN RURAL LAO PDR. Southeast Asian Journal of Tropical Medicine and Public Health, 45(1), 198-206. ( 1/2014 - Present )
    Although the individual contributions of smoked tobacco and indoor air pollution have been identified, there are very few studies that have characterized and measured the effects of inhaled particles from a wide range of personal, household, and community practices common in rural Asia. The objective of our study was to examine the association between environmental inhaled exposures and lung function among rural males of Lao PDR. In a sample of 92 males from rural Lao PDR, study subjects completed a survey on household exposures, a physical exam, and the following measures of lung function: FEV1, FVC, and the ratio of FEV1/FVC. Our findings were as follows: a) > 80% of the subjects were exposed to indoor cooking fires (wood fuel), animal handling, dust and dirt; b) 57.6% of subjects were in the impaired range (FEV1/FVC < 0.7); and c) animal handling was negatively associated (p<0.03) with FEV1 and FVC. Among males in rural Lao PDR, we found a high prevalence of chronic exposure to inhaled particles (animal handling, dust/dirt, smoke) and a high prevalence of impaired lung function. Findings from this pilot study indicate that associations between exposure to multiple sources of particulate matter common in rural areas and lung function need further investigation.
  • Martin R, Safaee S D, Somsamouth K, Mounivong B, Sinclair R, Bansal S, & Singh P N. (2013). Mixed Methods Pilot Study of Sharing Behaviors among Waterpipe Smokers of Rural Lao PDR: Implications for Infectious Disease Transmission. International Journal of Environmental Research and Public Health, 10(6), 2120-2132. ( 6/2013 - Present ) Link...
    To date, the sharing behaviors associated with the homemade tobacco waterpipe used in rural areas of the Western Pacific Region have not been studied. Evidence from studies of manufactured waterpipes raises the possibility of infectious disease transmission due to waterpipe sharing. The objective of our pilot study in rural Lao People's Democratic Republic (PDR) was to identify and measure the prevalence of waterpipe sharing behaviors. We first conducted ethnographic studies to investigate waterpipe-smoking behaviors. These findings were then used to develop an interviewer-administered household survey that was used in a sampling of waterpipe smokers from three villages of the Luang Namtha province of Lao PDR (n = 43). Sampled waterpipe smokers were predominantly male (90.7%), older (mean age 49, SD 13.79), married (95.4%), farmers (78.6%), and had completed no primary education. Pipes were primarily made from bamboo (92.9%). Almost all (97.6%) smokers were willing to share their pipe with others. At the last time they smoked, smokers shared a pipe with at least one other person (1.2 +/- 0.5 persons). During the past week, they had shared a pipe with five other persons (5.2 +/- 3.8 persons). The high prevalence of sharing behaviors among waterpipe smokers in rural Southeast Asia raises the possibility that this behavior provides important and unmeasured social network pathways for the transmission of infectious agents.
  • Lopez J R, Somsamouth K, Mounivong B, Sinclair R, & Singh P N. (2012). Carbon monoxide levels in water pipe smokers in rural Laos PDR. Tobacco Control, 21(5), 517-518. ( 9/2012 - Present ) Link...
  • Sinclair R G, Rose J B, Hashsham S A, Gerba C P, & Haas C N. (2012). Criteria for Selection of Surrogates Used To Study the Fate and Control of Pathogens in the Environment. Applied and Environmental Microbiology, 78(6), 1969-1977. ( 3/2012 - Present ) Link...
    This article defines the term surrogate as an organism, particle, or substance used to study the fate of a pathogen in a specific environment. Pathogenic organisms, nonpathogenic organisms, and innocuous particles have been used as surrogates for a variety of purposes, including studies on survival and transport as well as for method development and as "indicators" of certain conditions. This article develops a qualitative surrogate attribute prioritization process and allows investigators to select a surrogate by systematically detailing the experimental process and prioritizing attributes. The results are described through the use of case studies of various laboratories that have used this process. This article also discusses the history of surrogate and microbial indicator use and outlines the method by which surrogates can be used when conducting a quantitative microbial risk assessment. The ultimate goal of selecting a sufficiently representative surrogate is to improve public health through a health-based risk assessment framework. Under-or overestimating the resistance, inactivation, or movement may negatively impact risk assessments that, in turn, will impact health assessments and estimated safety levels. Reducing uncertainty in a risk assessment is one of the objectives of using surrogates and the ultimate motive for any experiment investigating potential exposure of a pathogen.
  • Sinclair R G, & Gerba C P. (2011). Microbial contamination in kitchens and bathrooms of rural Cambodian village households. Letters in Applied Microbiology, 52(2), 144-149. ( 2/2011 - Present ) Link...
    Aims: To quantify microbial contamination on kitchen and bathroom surfaces (fomites) in rural Cambodian homes and to compare these concentrations to similar data from the United States and Japan. Methods and Results: This study monitored the numbers of faecal coliforms (i.e. thermotolerant coliforms), total coliforms, Escherichia coli and heterotrophic plate count bacteria on household surfaces in a rural village of Cambodia. Faecal coliform levels in Cambodia were highest on moist locations such as the plastic ladle used for sink water, the toilet seat surface and the cutting board surface with 100-fold higher levels of faecal coliform bacteria than E. coli and 100-fold higher levels of faecal coliforms than the US and Japanese studies. Conclusions: A single public health intervention barrier, such as an improved latrine, is only partially effective for household sanitation. For complete sanitation, multiple environmental barriers may be necessary. These barriers occur in a house constructed with easily washable surfaces, a chlorinated water distribution system, house climate control and cleaning product availability. Significance and Impact of the Study: Results of this study can be used to emphasize the importance of increasing household environmental sanitation barriers.
  • Pepper I L, Brooks J P, Sinclair R G, Gurian P L, & Gerba C P. (2010). Pathogens and Indicators in United States Class B Biosolids: National and Historic Distributions. Journal of Environmental Quality, 39(6), 2185-2190. ( 11/2010 - Present ) Link...
    This paper reports on a major study of the incidence of indicator organisms and pathogens found within Class B biosolids within 21 samplings from 18 wastewater treatment plants across the United States. This is the first major study of its kind since the promulgation of the USEPA Part 503 Rule in 1993, and includes samples before and after the Part 503 Rule was promulgated. National distributions collected between 2005 and 2008 show that the incidence of bacterial and viral pathogens in Class B mesophilic, anaerobically digested biosolicts were generally low with the exception of adenoviruses, which were more prevalent than enteric viruses. No Ascaris ova were detected in any sample. In contrast, indicator organism numbers were uniformly high, regardless of whether they were bacteria (fecal coliforms) or viruses (phage). Indicators were not correlated with pathogen loads. Historic distributions were collected between 1988 and 2006 at one location in Tucson, AZ. By comparing data collected before and after 1993, the influence of the USEPA Part 503 Rule on indicator and pathogen levels within Class B biosolids can be inferred. In general, the bacterial indicators total and fecal coliforms decreased from the 1980s to present. Enteric virus concentrations after 1993 are much lower than those reported in other studies in the 1980s, although our values from 1988 to 1993 are not significantly different from our values obtained from 1994 to 2006. Presumably this is due to better and more consistent treatment of the wastewater, illustrating that the Part 503 Rule has been effective in reducing public exposure to pathogens relative to 17 yr ago. The percent reduction of both indicators and pathogens during anaerobic mesophilic digestion was between 94 and 99% for all organisms, illustrating that such treatment is effective in reducing pathogen loads.
  Books and Chapters
  •  Englande, A. J.; Lo, P.; Sinclair, R. G., Water quality and public health: case studies of Hurricane Katrina and the December 2004 tsunami in Thailand. In Cities of the future: towards integrated sustainable water and landscape management: proceedings of an international workshop held July 12-14, 2006 in Wingspread Conference Center, Racine, WI, Novotny, V.; Brown, P. R., Eds. IWA Publishing: London, 2007; p 52. On google books.   ( 6/2007 )