[By Stanslous Ngosa]
Climate change is likely to have considerable impact on food safety, both directly and indirectly, thereby placing public health at risk.
With changing rainfall patterns and increases in extreme weather events and the annual average temperature, we will begin to face the impact of climate change. Climate change and variability may have an impact on the occurrence of food safety hazards at various stages of the food chain, from primary production through to consumption.
There are multiple pathways through which climate related factors may impact food safety including changes in temperature and precipitation patterns, increased frequency and intensity of extreme weather events, ocean warming and acidification, and changes in contaminants’ transport pathways, among others.
Climate change may also affect socio-economic aspects related to food systems such as agriculture, animal production, global trade, demographics and human behaviour, which all influence food safety.
According to Ministry of Health assistant director in charge of environmental health, Cheleka Kaziya-Mulenga, since the 18th century, human activities have released large amounts of gases such as carbon dioxide and methane into the atmosphere. Mrs Mulenga explains that the vast majority of these gases have come from the burning of fossil fuels, industrial processes and deforestation.
The build-up of these gases, known as greenhouse gases, in the atmosphere, traps energy and acts like a blanket around the earth, contributing to an increase in the overall temperature of the earth’s atmosphere referred to as global warming.
This warming effect can influence and alter the earth’s climate, leading to climate change.
Changes can lead to more extreme weather events such as stronger storm systems, increased frequency of heavy rains and extended dry periods.
Access to sufficient amounts of safe and nutritious food is key to sustaining life and promoting good health.
According to the World Health Organisation (WHO), unsafe food containing harmful bacteria, viruses, parasites or chemical substances causes more than 200 diseases – ranging from diarrhoea to cancers. An estimated 600 million – almost 1 in 10 people in the world – fall ill after eating contaminated food and 420, 000 die every year, resulting in the loss of 33 million healthy life years.
Children under 5 years of age carry 40 per cent of the foodborne disease burden, with 125, 000 deaths every year.
The studies conducted by the European Food Safety Authority have identified climate change as a driver for emerging risks in food and feed safety in the mid- or long-term. Thus, improving our understanding of the possible effects of climate change on food safety is important, considering the implications it can have on food security.
The ability of microorganisms, for example bacteria, viruses and parasites, to survive and grow is influenced by the environment. Many foodborne organisms such as salmonella and campylobacter, grow well in warm, moist conditions. Warmer temperatures in summer and milder winters may increase the abundance of pests such as insects and rodents, which can spread foodborne organisms. Similarly, excess rainfall leading to flooding may aid the transportation of foodborne pathogens onto agricultural crops.
Climate change may also lead to emergence of new microbial hazards due to changes in the type of crops cultivated and the associated agricultural practices for crops, for instance, increased use of untreated animal waste to fertilizer crops. Furthermore, increased use of antimicrobials in treating farm animals due to spontaneous changes in the genetic make-up of a cell may lead to antibiotic-resistant pathogens.
Consumption of meat which has antimicrobial residues can lead to increased antibiotic resistance in humans.
Climate change may affect the nature, level and transmission of various chemicals, contaminants and toxins, hence affecting the safety of our foods. Changes in climatic conditions tend to affect what crops are grown and how they are grown in different countries.
High prevalence of pests, rodents and weed changes, thereby affecting change in chemical usage such as pesticides. Emergence of pests such as army worms will require use of pesticides and if proper monitoring on the use is not done, pesticide residues may end up in the crops and have negative impact on human health.
Toxins such as mycotoxins are formed by some fungi as they grow on crops such as groundnuts, maize and other cereals. They can be consumed through contaminated crops or indirectly through animal products (e.g. meat or milk from animals) that have eaten contaminated feed. The production of these toxins may be affected by temperature and moisture conditions. Mycotoxins can cause a wide range of toxic effects in humans as mycotoxins can cause cancers or attack specific organs such as the liver and kidneys.
To ensure safety of food, there is need for controls in the food safety continuum from farm to fork through food monitoring, enforcement of legislation and scientific research. This will provide consumers with continued protection against existing and emerging food safety issues which may be associated with climate change.
To address the matter, Mrs Mulenga says government has developed the Health National Adaptation Plan to climate change whose focus is to strengthen the sector’s capacity to respond to climate change and increase community resilience. Food safety monitoring has also been strengthened in all the provinces by ensuring that Inspectors are equipped with skills and tools. The Government, through the Ministry of Health, has conducted vulnerability assessment in all the provinces to assess the vulnerable areas and plan for mitigation.
Furthermore, the government has developed the National Contingency Plan that incorporates food safety, nutrition and epidemic preparedness.
The government has also developed protocol for water quality monitoring to ensure safety of drinking water for communities.
With the uncertainty regarding the risk of climate change on food safety, government will ensure that food safety infrastructure is strengthened through continuous reviews and improvement. Government will also continue to strengthen stakeholder collaboration among food agencies, food business operators and consumers.
The author is head of media relations at the Ministry of Health.