The first rainwater is not considered pure. It's contaminated by atmospheric pollutants like dust, germs, bacteria, and dissolved gases collected as it falls.
Why the First Rain is Impure
-
Atmospheric Pollutants: The initial rainfall washes away accumulated pollutants from the atmosphere. This includes airborne particles, industrial emissions, and other contaminants. As noted in several sources, the first shower acts as a cleansing agent, carrying these impurities to the ground.
-
Contamination Sources: The level of contamination depends on the surrounding environment. Areas with high pollution levels will have more impurities in the first rainfall compared to cleaner regions.
-
Not Potable: Therefore, the first rainwater is generally unsafe for drinking or direct consumption without proper filtration and purification.
Practical Considerations
While the first rain may be impure, subsequent rainfall often becomes cleaner as the atmosphere is progressively cleansed. Several sources mention collecting rainwater after the initial downpour for various uses, including irrigation and brewing. However, always ensure proper filtration and treatment before use, especially for consumption.
-
Collection Methods: Using rain barrels to collect rainwater is popular, but the initial water should be discarded. Many sources suggest letting the first period of rainfall wash the surfaces of collection areas before collecting the water for use.
-
Testing: For applications like brewing, some sources recommend having the rainwater tested to ensure it meets the required purity standards before use.
-
Gardening: Collecting rainwater for gardening is common, but it's important to consider local environmental conditions and potential contaminants.
