Dañino vs. nocivo vs. perjudicial
In Spanish, the words 'dañino', 'nocivo', and 'perjudicial' all translate to 'harmful' in English, but each has its own nuances and contexts where it is most appropriate.
Dañino
'Dañino' refers to something that causes damage or harm. It is commonly used to describe anything that negatively affects health, environment, or wellbeing.
El tabaco es muy dañino para la salud.
(Tobacco is very harmful to health.)
Los insecticidas pueden ser dañinos para las abejas.
(Insecticides can be harmful to bees.)
Nocivo
'Nocivo' often implies something that is injurious or detrimental, particularly in a way that is toxic or chemically damaging. It is frequently used in scientific and environmental contexts.
El uso de productos químicos nocivos en la agricultura afecta el ecosistema.
(The use of harmful chemicals in agriculture affects the ecosystem.)
La exposición prolongada a radiación nociva puede causar cáncer.
(Prolonged exposure to harmful radiation can cause cancer.)
Perjudicial
'Perjudicial' generally means something that causes damage or detriment, especially in terms of long-term effects on health, welfare, or finances.
Trabajar muchas horas sin descanso puede ser perjudicial para la salud mental.
(Working long hours without rest can be detrimental to mental health.)
El consumo excesivo de azúcar es perjudicial para los niños.
(Excessive sugar consumption is detrimental to children.)
Summary
While 'dañino' (harmful) suggests general harm or damage mostly towards health and wellbeing, 'nocivo' (injurious) typically refers to toxicological and environmental harm, and 'perjudicial' (detrimental) describes broader long-term negative effects on various aspects of life.