Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-4 (of 4 Records) |
Query Trace: Baloch MA[original query] |
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A systems analysis of irrigation water quality in an environmental assessment of an E. coli O157: H7 outbreak in the United States linked to iceberg lettuce
Gelting RJ , Baloch MA , Zarate-Bermudez M , Hajmeer MN , Yee JC , Brown T , Yee BJ . Agric Water Manag 2015 150 (3) 111-118 A foodborne Escherichia coli O157:H7 outbreak in December 2006 included 77 illnesses reported in Iowa and Minnesota. Epidemiologic investigations by health departments in those states and the U.S. Centers for Disease Control and Prevention (CDC) identified shredded iceberg lettuce (Lactuca sativa L.) as the vehicle of transmission. The U.S. Food and Drug Administration (FDA) and Minnesota and California public health agencies traced the lettuce to several growing regions in California based on information from a lettuce processor in Minnesota.Samples from an environmental investigation initiated by the California Food Emergency Response Team (CalFERT) revealed a genetic match between the outbreak strain and environmental samples from a single farm, leading to an in-depth systems-based analysis of the irrigation water system on that farm. This paper presents findings from that systems-based analysis, which assessed conditions on the farm potentially contributing to contamination of the lettuce. The farm had three sources of irrigation water: groundwater from onsite wells, surface water delivered by a water management agency and effluent from wastewater lagoons on nearby dairy farms. Wastewater effluent was blended with the other sources and used only to irrigate animal feed crops. However, water management on the farm, including control of wastewater blending, appeared to create potential for cross-contamination. Pressure gradients and lack of backflow measures in the irrigation system might have created conditions for cross-contamination of water used to irrigate lettuce. The irrigation network on the farm had evolved over time to meet various needs, without an overall analysis of how that evolution potentially created vulnerabilities to contamination of irrigation water. The type of systems analysis described here is one method for helping to ensure that such vulnerabilities are identified and addressed. A preventive, risk-based management approach, such as the Water Safety Plan process for drinking water, may also be useful in managing irrigation water quality. |
Groundwater vulnerability assessments: prioritizing water safety in times of austerity
Baloch MA . J Environ Health 2013 76 (4) 40-2 For communities using private or unregulated drinking water wells, groundwater vulnerability to microbial contamination poses a significant public health risk. Historically, a significant number of drinking-water-associated waterborne illness outbreaks and contamination events have been attributed to unregulated water systems (Craun & Calderon, 2003; DeSimone, Hamilton, & Gilliom, 2009; Yoder et al., 2008). Although many environmental health programs are required to inspect and test private wells only at the time of permitting (when a new well is constructed or repaired), illnesses and problems associated with these systems constitute a major part of water safety initiatives pursued by these programs. | | In the wake of government austerity measures, many environmental health permitting programs will curtail services associated with private wells. In its efforts to support local environmental health programs, the Centers for Disease Control and Prevention’s Environmental Health Specialists Network (EHS-Net) Water Program has developed a groundwater vulnerability assessment tool, Land-use Hydrology and Topography (LHT), piloted in 18 counties in the state of Georgia to assess the effectiveness of this approach for identifying unregulated wells for prioritized intervention (Baloch & Sahar, 2011). This column presents a case for using a groundwater vulnerability mapping approach to prioritize intervention programs for those private or individual wells most vulnerable to contamination. |
The food-water nexus: irrigation water quality, risks to food safety, and the need for a systems-based preventive approach
Gelting RJ , Baloch MA . J Environ Health 2012 75 (3) 40-41 This year’s World Water Day focused on | the food-water nexus with the theme | “Water and Food Security: The World is | Thirsty Because We are Hungry.” While much | of the emphasis under this theme focused on | the quantities of water used for food production, the quality of water is also important to | that function. Water quality can also have significant effects on health. In this context, the | quality of irrigation water can have profound | impacts on the microbiological integrity of | food. Irrigation water has been implicated as a | possible source of pathogens in produce linked | to major disease outbreaks in the U.S. and Europe. Many sources of irrigation water are subject to inputs of pathogenic loads from point | and nonpoint sources stemming from multiple | land uses in watersheds (Pachepsky, Shelton, | Mclain, Patel, & Mandrell, 2011). Research on | the potential effects of irrigation water quality on food safety therefore requires a systemsbased environmental assessment on the watershed scale that accounts for various factors that | may influence irrigation water quality. |
Irrigation water issues potentially related to the 2006 multistate E. coli O157:H7 outbreak associated with spinach
Gelting RJ , Baloch MA , Zarate-Bermudez MA , Selman C . Agric Water Manag 2011 98 (9) 1395-1402 A multistate Escherichia coli O157:H7 outbreak in August and September 2006 was found to be associated with consumption of fresh bagged spinach traced to California. The California Food Emergency Response Team (CALFERT), consisting of personnel from the California Department of Public Health Food and Drug Branch (FDB) and the U.S. Food and Drug Administration (FDA) undertook an environmental investigation to determine how and why the spinach became contaminated. At the invitation of FDA and FDB, the Centers for Disease Control and Prevention (CDC) also participated in the environmental investigation. This paper presents findings from the portion of the environmental investigation focusing on environmental factors related to irrigation water that may have contributed to contamination of the spinach and hence to the outbreak. Analysis of the available data suggests that depths to groundwater and groundwater-surface water interactions may pose risks to ready-to-eat crops. These risks should be further evaluated and quantified to understand and identify the factors that contributed to this and similar outbreaks. One implication of this analysis is the need to continue to conceptually broaden the scope of produce-related outbreak investigations. Where feasible, investigation strategies should integrate possible contamination sources beyond those actually found on the farms that are identified as sources of produce involved in outbreaks. |
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