Final answer:
Smaller particles, less than 10 micrometres (PM10) and especially those less than 2.5 micrometres (PM2.5), are more closely linked to mortality and respiratory diseases because they penetrate deeply into the lungs. In medical treatments, smaller nanoparticles (around 70 nanometers) show better retention at tumor sites, influencing treatment efficacy.
Step-by-step explanation:
Regarding the question What size of particle is more linked to mortality and disease?, research indicates that smaller particles, particularly those less than 10 micrometres (PM10) and even more so particles less than 2.5 micrometres (PM2.5), are linked to higher risks of mortality and disease. These fine particles are capable of penetrating deeply into the lungs, where they can cause a variety of respiratory diseases such as pneumonia, bronchitis, and asthma.
Beyond implications for respiratory illness, smaller particle sizes can also impact the efficiency of drug delivery in medical treatments, such as using nanoparticles to target tumor cells. In oncology, studies have shown that nanoparticles around 70 nanometers are retained better at tumor sites than larger ones, which can influence treatment outcomes.