Although China has experienced unprecedented economic growth during the last 15 years, pulling hundreds of millions of its citizens out of poverty, air and water pollution still cause a significant number of deaths and diseases in the country.
A Review in this week’s The Lancet Special Issue on China examines air and water quality concerns in China, and the steps the nation has recently taken towards improvements in these areas. The Review is written by Dr Junfeng Zhang, University of Medicine and Dentistry of New Jersey-School of Public Health, USA, and Dr Justin V Remais, Rollins School of Public Health, Emory University, Atlanta, GA, USA, and colleagues.
Along with economic growth from industrialization – which has improved health and quality of life indicators – has come an increase in the release of chemical toxins into the environment, as well as the rate of environmental disasters, with serious effects on health.
China’s cities have some of the worst levels of air quality in the world, and industrial water pollution has become a widespread health hazard. Climate-warming greenhouse gas emissions from energy use are increasing rapidly.
Global climate change will inevitably deepen China’s environmental health troubles, with potentially disastrous outcomes from major shifts in temperature and precipitation.
The authors say: “Facing the overlap of traditional, modern, and emerging environmental dilemmas, China has committed substantial resources to environmental improvement. The country has the opportunity to address its national environmental health challenges and to assume a central role in the international effort to improve the global environment.”
China’s population is exposed to both traditional and modern environmental risk factors. Traditional risks include poor hygiene and indoor air pollution from burning of coal, wood, and crop residue (solid fuels). Modern risks that are linked to industrialisation and urbanisation include outdoor air pollution and industrial waste.
Indoor air pollution from burning solid fuels is one of the major environmental health risk factors, and leads to about 420 000 premature deaths annually. The major health outcomes associated with air pollution include COPD (chronic obstructive pulmonary disease), acute lower respiratory infection, and lung cancer. COPD causes 1•3 million deaths per year in China, and solid fuel use more than triples COPD incidence. Likewise, solid fuel use is a major risk factor for acute lower respiratory tract infections, which mainly kill young children and therefore contribute more lost life-years per death than do diseases that affect older people. Programmes such as the National Improved Stoves initiative have helped reduce this burden (180 million stoves introduced since 1980s) but stove quality is variable and success of pollutant reduction is highly dependent on this and the presence or absence of a chimney.
Outdoor air pollution in China originates from many sources, including residential and industrial coal combustion, an expanding transport sector, industrial chemical releases, outdoor burning of agricultural waste, and dust from construction, roads, and deserts. The economic cost of mortality and morbidity that results from outdoor air pollution in a typical Chinese city was about 10% of that city’s gross domestic product in 2000, and, dependent on future technology and policies, this cost is predicted to range from 8% to 16% by 2020.
A high number of lakes and major rivers in China are classified as severely polluted, with only half of China’s 200 major rivers and less than a quarter of its 28 major lakes and reservoirs suitable for use as drinking water after treatment. Water pollution is especially severe in rural areas, where few drinking water and sanitation services were in place until the late 1980s and early 1990s, when China’s Patriotic Health Campaign invested enormous resources in improvement of these services. However, coverage remains low. The authors say: “To confront deteriorating rural water quality, major investments in basic sanitation services will be needed to interrupt transmission of water-related pathogens, some of which – such as schistosome parasites – have re-emerged in regions that had previously achieved elimination.”
Access to piped water increased from 30% of the population in 1985 to 77% in 2007 and, despite a massive increase in urban population, access for urban residents reached nearly 94% in 2007. Partly as a result of this increase in access to piped water, there has been a reduction in water-related infectious diseases.
Growth in China’s industrial contamination shows few signs of abatement. The past 20 years have witnessed unregulated and increased industrial discharges and excessive use of fertilisers and pesticides in agricultural areas. Recent progress to limit industrial water pollution includes large reported reductions (60-70% by mass) in yearly emissions of arsenic and mercury to water, and construction of more than 60 000 industrial waste water treatment plants. Yet in the absence of monitoring and oversight, improvements to water quality from these efforts have not been documented. In response to the fragmentation of oversight, a pilot water quality surveillance network was established in 2007 covering five provinces and Beijing and Shanghai. The network was designed to comprehensively monitor drinking water quality at various points, including at sources, distribution systems, and point of use, along with human health status. The authors say: “The Ministry of Health intends to expand this programme nationally: an ambitious plan that could rapidly improve the safety of China’s drinking water resources.”
China has successfully reduced extreme poverty through economic growth but, until very recently, has overlooked the growing inequalities in income, health, access to clean water, sanitation, and cleaner fuels. But the authors point out the very rapid progress that can be made when there is political pressure, such as the large cut in air pollution during the 2008 Beijing Summer Olympics.
The authors say: “A greater emphasis on regulatory enforcement is needed, to include substantial fines and criminal penalties, and systems to objectively assess the success of specific regulatory actions must be instituted. China’s recently released first National Environment and Health Action Plan emphasises the need to coordinate activities across many sectors and ministries.”
And referring also to China’s commitments to greenhouse gas reduction irrespective of the actions of other counties, the authors conclude: “These environmental goals will have a substantial effect if achieved alongside a firm commitment from the Chinese Government to formulate, implement, and enforce effective environmental health policies.”
“Environmental health in China: progress towards clean air and safe water”
Junfeng Zhang, Denise L Mauzerall, Tong Zhu, Song Liang, Majid Ezzati, Justin V Remais
Lancet 2010; 375: 1110-19
Edited by Christian Nordqvist