Benefits & Limitations of Strategies to Control Water-Related Diseases (Cambridge International IGCSE Environmental Management)

Benefits & limitations of strategies to control water-related diseases

• Water-related diseases such as malaria and cholera can be reduced through prevention, control of transmission, and treatment

  • These strategies vary in cost, effectiveness and whether they rely on individual actions or large-scale government systems

• Understanding the benefits and limitations helps explain why some diseases are easier to control than eradicate

Malaria

Benefits of malaria control strategies

• Personal protection (nets, repellents, vaccination, antimalarial drugs) reduces mosquito-to-human transmission

  • This lowers the number of infections and protects vulnerable groups

• Vector control (draining stagnant water, spraying insecticides, biological control) reduces mosquito populations

  • This decreases the number of bites and slows the spread of the parasite

• Strategies that destroy the Plasmodium parasite (drugs and vaccines) target the disease directly

  • This can reduce the parasite in the human population
  • This increases the chance of long-term reduction in malaria cases

Limitations of malaria control strategies

• Destroying the parasite is more effective in the long term

  • This is because removing the parasite could eliminate malaria entirely
  • But these strategies are expensive and often require medical professionals

• Controlling mosquito breeding (e.g. draining stagnant water) is cheaper and can be done by communities

  • However, these methods only reduce mosquito numbers temporarily and do not remove the parasite

• Mosquitoes are developing resistance to insecticides

  • This makes spraying less effective over time

• The malaria parasite is becoming resistant to some antimalarial drugs

  • This reduces the effectiveness of treatment and prevention

• Improvements in diagnosis, treatment and prevention have reduced deaths but this has not led to full elimination because transmission continues where mosquitoes remain

Cholera

Benefits of cholera control strategies

• Personal actions such as handwashing and boiling water are effective at preventing infection

  • These strategies are inexpensive and can be done by individuals or families

• Chlorination of water supplies kills cholera bacteria

  • This helps protect entire communities where safe water is provided

• Vaccines reduce the number of severe cases during outbreaks

  • They provide important short-term protection in high-risk regions

• Improved sanitation and sewage treatment stop faecal contamination of water

  • This removes the source of the bacteria and greatly reduces long-term risk

Limitations of cholera control strategies

• Personal actions are useful but depend on consistent behaviour

  • Outbreaks may occur when people cannot access soap, fuel for boiling water or chlorine tablets

• Large-scale sanitation systems are more effective

  • These are very expensive and require government funding, planning and maintenance
  • Without proper maintenance, sewage can leak and reintroduce cholera bacteria

• Cholera vaccines do not give lifelong immunity

  • They must be used alongside other strategies, such as sanitation and clean water supply

• Areas lacking safe sewage disposal are at continuous risk

  • This means that outbreaks may return quickly if water quality drops

Exam Hint For malaria, it is important to be able to compare strategies that target the mosquito with those that target the parasite. Examiners want to see that you understand the difference in long-term effectiveness of different strategies.

In evaluation questions, show awareness that low-cost personal actions help in the short term, while expensive infrastructure (sewage treatment, clean water systems) is essential for long-term disease control. This kind of balanced reasoning will help you reach the top level of the mark scheme.