What concentration of pollen grains per cubic meter of air is considered unlikely to produce allergic reactions?

A concentration of 33 pollen grains per cubic meter of air is recognized as a threshold that is generally unlikely to trigger allergic reactions in most individuals who are sensitive to pollen. Allergic responses are typically associated with higher concentrations where the likelihood of encountering sufficient allergenic material increases.

While individual sensitivities can vary, studies and reports have established that concentrations below this level typically do not generate significant immune responses, thereby minimizing the chances of an allergic reaction. Higher pollen counts, particularly above 100 grains per cubic meter, can lead to heightened symptoms for individuals with allergic conditions. Therefore, a concentration near or below 33 tends to ensure fewer allergic reactions are reported among the sensitive population.

The values above 33, including those listed at 100, 250, and 1000, indicate progressively larger amounts of pollen, which correlate with increased odds for allergic responses. Thus, 33 serves as a more definitive indicator for safety concerning pollen exposure.