Environmental Risk Assessment

The measurement and modelling of health impacts arising from the land spreading of biosolids on agricultural land.

Researcher: Rachel Clarke

The land spreading of biosolids (sewage sludge) is the preferred option for human waste disposal in Ireland. Infact we spread 98% of all human waste on agricultural land. Ninety six percent of this waste is treated. 

The spreading of biosolids provide much needed nutrients to the soil (nitrogen, phosphorus and potassium), however, they may also harbor contaminants (i.e. metals, E. coli, pharmaceuticals and chemicals) that may enter surface waters through runoff following rainfall events or be up-taken into plants and subsequently enter the human food chain.

The objective of my research is to conduct a quantitative risk assessment model to evaluate the likelihood of contaminants entering the food chain following the land spreading of biosolids.

A drinking water model was developed to simulate drinking water treatment following abstraction from surface waters using literature data and data generated from project partners.

A similar quantitative risk assessment model was developed for the plant up-take to measure the contaminant up-take into plants, animal consumption (cow) and the concentration of the contaminant in the meat and milk of the cow.

A human risk assessment model was then developed incorporating the results from the drinking water and plant up-take models to assess if there is a risk to human health through the land spreading of biosolids on agricultural land. 

Microbial Risk Assessment to quantify the risk norovirus poses to consumers of Irish oysters.

Researcher: Kevin Hunt

It is important that the food we eat is safe and clean. When food is contaminated by biological hazards like viruses and bacteria, it can lead to severe illness, and even death.

The majority of cases of food-related viral illness come from norovirus, a highly infectious gastroenteric virus. For a variety of reasons, shellfish consumers can be particularly vulnerable to norovirus infection.

My project uses methods of microbial risk assessment to usefully quantify the risk that norovirus poses to consumers of Irish oysters. I explore how norovirus accumulates in contaminated oysters, and what this might mean for the average consumer. Once the risk of illness can be estimated, the next step will be to assess the most effective ways of managing it.

Effective safety standards reduce disease and improve consumer confidence. My project provides data on virus behaviour which will then lead to models that estimate risk reduction. The results should prove useful to farmers, regulators and, above all, consumers.