Welcome!

News Feed Item

Stricter Controls Of Wastewater Reuse On Crops Needed To Meet WHO Guidelines

Scientific study appearing in the journal Risk Analysis raises public health concerns

WASHINGTON, March 5, 2014 /PRNewswire-USNewswire/ -- Wastewater used to irrigate agricultural crops in countries where water is scarce may contribute to significant public health risks such as diarrheal disease in children from rotavirus. A new study of these risks found that wastewater used to irrigate vegetable plots in Asian countries poses health risks that may exceed World Health Organization (WHO) guidelines. The authors recommend that stricter wastewater regulation may be needed to protect the health of farmers and consumers worldwide.

The new findings come at a time when climate change and increasing population pressure requires the development of methods to produce more food with fewer irrigation resources. Wastewater reuse is an economical method to grow food, but wastewater carries microorganisms such as viruses, bacteria and protozoa that can contaminate food and cause disease. Asia accounts for the majority of the world's reuse of wastewater in irrigation, and given that China is the world's most populous country, millions of people may be exposed to health risks from contamination. However, normal cooking temperatures and food preservation strategies can reduce the risks posed by microorganisms and viruses.

Although health studies can trace the incidence of disease in a population, conducting extensive experimental work and collecting sufficient data can be cost-prohibitive. Food systems researchers Hoi-Fei Mok and Andrew J. Hamilton of The University of Melbourne in Australia instead created a statistical model to characterize the health risks posed by wastewater used to grow Asian vegetables. The reach of the Asian vegetable market extends well beyond Asia. Their paper, "Exposure factors for wastewater-irrigated Asian vegetables and a probabilistic rotavirus disease burden model for their consumption," recently appeared in the electronic version of the journal Risk Analysis, published by the Society for Risk Analysis.

The researchers first determined the volume of water retained by three commonly grown Asian vegetables, and then used a statistical model to estimate rotavirus disease burdens associated with wastewater irrigation. Rotavirus is associated with diarrheal disease in children, and was chosen as the focus of the study because diarrheal disease is associated with 74 percent of wastewater-related deaths, 90 percent of which occur in children. According to the WHO, diarrheal disease is the second leading global cause of death in children under five years old, and is responsible for the deaths of approximately 760,000 children each year. Diarrhea can last several days, and can leave the body without the water and salts that are necessary for survival. Most people who die from diarrhea actually die from severe dehydration and fluid loss.

Based on their findings, the researchers concluded that the probability curves of the annual disease burden "exceeded the WHO's threshold for acceptable level of risk from wastewater reuse by two to three orders of magnitude." Some vegetables posed greater risk than others, because leaf shape affects the amount of wastewater and contaminants that are retained. Vegetables such as bok choy posed the least risk and choy sum the greatest risk, whereas lettuce and gai lan had similar risk profiles. The viral decay rate also varies depending on the plant. The authors say that more research on the rate of viral decay on various crops would increase the accuracy of risk estimations.

The probability of rotavirus infection is affected by uncertainty in virus concentration and variation in vegetable consumption. For example, the mean daily per capita lettuce consumption in Australia is 21.81 grams lettuce/person day, compared to a mean of 171.94 grams lettuce / person day in China, although there is seasonal variation in consumption patterns.

The dose-response model, which characterizes the relationship between exposure level to contaminants and the probability of developing disease, is a source of uncertainty in the risk assessment. The rotavirus infection rates were based on data from an infectivity trial in adults, but rotavirus primarily affects children. Lower doses induce infectivity in children faster than adults, so the estimated disease burdens from the researchers' statistical model may underestimate the actual risk to children. Collecting rotavirus infectivity data for children would improve the accuracy of risk assessments of the threat.

Although there are Chinese national standards and regulations for the reuse of wastewater, they present only threshold concentrations for bacteria such as E. coli, not viruses. Furthermore, while there are regulations relating to water quality, there is no guideline for risk management around wastewater reuse in China. The risk management approach involves more pro-active identification and management of risk, rather than relying on post-treatment testing for managing reuse schemes. Considering the global increase in wastewater use for agricultural irrigation, assessing the health risks from reuse schemes is necessary to develop better wastewater management policies to protect public health.

Risk Analysis: An International Journal is published by the nonprofit Society for Risk Analysis (SRA). SRA is a multidisciplinary, interdisciplinary, scholarly, international society that provides an open forum for all those who are interested in risk analysis. Risk analysis is broadly defined to include risk assessment, risk characterization, risk communication, risk management, and policy relating to risk, in the context of risks of concern to individuals, to public and private sector organizations, and to society at a local, regional, national, or global level. www.sra.org

Contact: Steve Gibb, 202.422.5425 [email protected] to arrange an interview with the author(s).

Note to editors: The complete article is available upon request from Steve Gibb or here:
http://onlinelibrary.wiley.com/doi/10.1111/risa.12178/full

This news release was issued on behalf of Newswise™. For more information, visit http://www.newswise.com.

SOURCE Society for Risk Analysis

More Stories By PR Newswire

Copyright © 2007 PR Newswire. All rights reserved. Republication or redistribution of PRNewswire content is expressly prohibited without the prior written consent of PRNewswire. PRNewswire shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon.

Latest Stories
Things are changing so quickly in IoT that it would take a wizard to predict which ecosystem will gain the most traction. In order for IoT to reach its potential, smart devices must be able to work together. Today, there are a slew of interoperability standards being promoted by big names to make this happen: HomeKit, Brillo and Alljoyn. In his session at @ThingsExpo, Adam Justice, vice president and general manager of Grid Connect, will review what happens when smart devices don’t work togethe...
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
@DevOpsSummit taking place June 6-8, 2017 at Javits Center, New York City, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. @DevOpsSummit at Cloud Expo New York Call for Papers is now open.
"There's a growing demand from users for things to be faster. When you think about all the transactions or interactions users will have with your product and everything that is between those transactions and interactions - what drives us at Catchpoint Systems is the idea to measure that and to analyze it," explained Leo Vasiliou, Director of Web Performance Engineering at Catchpoint Systems, in this SYS-CON.tv interview at 18th Cloud Expo, held June 7-9, 2016, at the Javits Center in New York Ci...
SYS-CON Events announced today that Dataloop.IO, an innovator in cloud IT-monitoring whose products help organizations save time and money, has been named “Bronze Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Dataloop.IO is an emerging software company on the cutting edge of major IT-infrastructure trends including cloud computing and microservices. The company, founded in the UK but now based in San Fran...
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud strategy.
Internet of @ThingsExpo, taking place June 6-8, 2017 at the Javits Center in New York City, New York, is co-located with the 20th International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. @ThingsExpo New York Call for Papers is now open.
In the next five to ten years, millions, if not billions of things will become smarter. This smartness goes beyond connected things in our homes like the fridge, thermostat and fancy lighting, and into heavily regulated industries including aerospace, pharmaceutical/medical devices and energy. “Smartness” will embed itself within individual products that are part of our daily lives. We will engage with smart products - learning from them, informing them, and communicating with them. Smart produc...
Providing the needed data for application development and testing is a huge headache for most organizations. The problems are often the same across companies - speed, quality, cost, and control. Provisioning data can take days or weeks, every time a refresh is required. Using dummy data leads to quality problems. Creating physical copies of large data sets and sending them to distributed teams of developers eats up expensive storage and bandwidth resources. And, all of these copies proliferating...
SYS-CON Events announced today that Catchpoint, a leading digital experience intelligence company, has been named “Silver Sponsor” of SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. Catchpoint Systems is a leading Digital Performance Analytics company that provides unparalleled insight into your customer-critical services to help you consistently deliver an amazing customer experience. Designed for digital business, C...
“DevOps is really about the business. The business is under pressure today, competitively in the marketplace to respond to the expectations of the customer. The business is driving IT and the problem is that IT isn't responding fast enough," explained Mark Levy, Senior Product Marketing Manager at Serena Software, in this SYS-CON.tv interview at DevOps Summit, held Nov 4–6, 2014, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Catchpoint Systems, Inc., a provider of innovative web and infrastructure monitoring solutions, has been named “Silver Sponsor” of SYS-CON's DevOps Summit at 18th Cloud Expo New York, which will take place June 7-9, 2016, at the Javits Center in New York City, NY. Catchpoint is a leading Digital Performance Analytics company that provides unparalleled insight into customer-critical services to help consistently deliver an amazing customer experience. Designed ...
More and more brands have jumped on the IoT bandwagon. We have an excess of wearables – activity trackers, smartwatches, smart glasses and sneakers, and more that track seemingly endless datapoints. However, most consumers have no idea what “IoT” means. Creating more wearables that track data shouldn't be the aim of brands; delivering meaningful, tangible relevance to their users should be. We're in a period in which the IoT pendulum is still swinging. Initially, it swung toward "smart for smart...
WebRTC sits at the intersection between VoIP and the Web. As such, it poses some interesting challenges for those developing services on top of it, but also for those who need to test and monitor these services. In his session at WebRTC Summit, Tsahi Levent-Levi, co-founder of testRTC, reviewed the various challenges posed by WebRTC when it comes to testing and monitoring and on ways to overcome them.
The emerging Internet of Everything creates tremendous new opportunities for customer engagement and business model innovation. However, enterprises must overcome a number of critical challenges to bring these new solutions to market. In his session at @ThingsExpo, Michael Martin, CTO/CIO at nfrastructure, outlined these key challenges and recommended approaches for overcoming them to achieve speed and agility in the design, development and implementation of Internet of Everything solutions with...