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04 June 2019 | Story Valentino Ndaba | Photo Charl Devenish
Prof Cathryn Tonne
Air pollution not only costs lives, it costs money too. Pictured is Prof Cathryn Tonne presenting a guest lecture on air pollution at the Bloemfontein Campus.

Health effects associated with ambient air pollution (AAP) have been well documented. Subsequently, the relationship between pollution and financial outcomes have also become a focus for case studies globally. An Environmental Research journal article revealed that “low and middle-income countries are disproportionately affected by the global burden of adverse health effects caused by AAP”. 

A high price to pay

In 2012, high concentrations of air pollution caused 7.4% of all deaths, costing South Africa up to 6% of its Gross Domestic Product. According to the recent International Growth Centre study conducted by senior University of Cape Town researchers, this is a direct consequence of the country’s heavy dependence of fossil fuels, a source of health-damaging air pollution and greenhouse pollutants.

Stunted human and economic growth

These South African statistics are attested to by Prof Cathryn Tonne who recently presented a guest lecture on air pollution which was hosted by the University of the Free State (UFS) Business School.

“Air pollution can affect economic development through several pathways, and health is an important one. Air pollution is linked to shorter life expectancy, chronic disease, asthma exacerbation and many other health outcomes that result in absenteeism from work and school. These have large direct costs to the health system.” 

Prof Tonne says that air pollution exposure in children is linked to reduced cognitive development, with important impacts on human capital. As a result, children are not reaching their full potential in terms of neurodevelopment, which has an effect on their income prospects and the economy as a whole. 

Resolving a looming disaster

Technology may be employed to radically clean the air. Cities need to lead in the reduction of air pollution by promoting renewable energy, using active transport such as walking or cycling, and investing in infrastructure to make this safe and attractive. 

With researchers playing a major role in strengthening the case for aggressive air pollution control, the government needs to implement policies in order to control sources of air pollution. This global health and economic issue also requires individuals and communities to play their part to improve air quality.

News Archive

Well-established root system important for sustainable production in semi-arid grasslands
2015-02-24

Plot layout where production and root studies were done
Photo: Supplied

The importance of a well-established root system for sustainable production in the semi-arid grasslands cannot be over-emphasised.

A study of Prof Hennie Snyman from the Department of Animal and Wildlife and Grassland Sciences at the University of the Free State is of the few studies in which soil-water instead of rainfall has been used to estimate above- and below-ground production of semi-arid grasslands. “In the past, plant ecological studies have concentrated largely on above-ground parts of the grassland ecosystem with less emphasis on root growth. This study is, therefore, one of the few done on root dynamics in drier areas,” said Prof Snyman.

The longevity of grass seeds in the soil seed bank is another aspect that is being investigated at present. This information could provide guidelines in grassland restoration.

“Understanding changes in the hydrological characteristics of grassland ecosystems with degradation is essential when making grassland management decisions in arid and semi-arid areas to ensure sustainable animal production. The impact of grassland degradation on productivity, root production, root/shoot ratios, and water-use efficiency has been quantified for the semi-arid grasslands over the last 35 years. Because of the great impact of sustainable management guidelines on land users, this study will be continuing for many years,” said Prof Snyman.

Water-use efficiency (WUE) is defined as the quantity of above- and/or below-ground plant produced over a given period of time per unit of water evapotranspired. Sampling is done from grassland artificially maintained in three different grassland conditions: good, moderate, and poor.

As much as 86, 89 and 94% of the roots for grasslands in good, moderate and poor conditions respectively occur at a depth of less than 300 mm. Root mass is strongly seasonal with the most active growth taking place during March and April. Root mass appears to be greater than above-ground production for these semi-arid areas, with an increase in roots in relation to above-ground production with grassland degradation. The mean monthly root/shoot ratios for grasslands in good, moderate, and poor conditions are 1.16, 1.11, and 1.37 respectively. Grassland degradation lowered above- and below-ground plant production significantly as well as water-use efficiency. The mean WUE (root production included) was 4.79, 3.54 and 2.47 kg ha -1 mm -1 for grasslands in good, moderate, and poor conditions respectively.

These water-use efficiency observations are among the few that also include root production in their calculations.

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