From simple considerations TSPM: Stands for Total Suspended Particulate Matter and would essentially be the concentration one would get when a high-volume bulk sampling is done on a filter substrate.

RSPM is that fraction of TSPM which is readily inhaled by humans through their respiratory system and in general, considered as particulate matter with their diameter (aerodynamic) less than 2.5 micrometers. Larger particles would be filtered in the nasal duct.

PM10 is a subset of TSPM and stands for particulate matter with aerodynamic diameter less than 10 micrometer.

However, these are all some rules for convenience; in practice, most of the air-borne particles are non-spherical and it is difficult to assign a diameter. Further aerodynamic diameter is also a mathematical concept (an imaginary sphere having unit bulk-density and the same settling speed as that of the actual particle) and hence is related through the density (mass per unit volume) of the particle.

The attached paper will answer your question.

Thank you Uwe Kaminski

Under an experimental point of view, cut-off is not the only parameter you must consider, because also the flow rate of the sampler is important. For example US and European PM10 reference methods provide different flow rate so that the amount of PM you collect for the same cut off can be different

From simple considerations TSPM: Stands for Total Suspended Particulate Matter and would essentially be the concentration one would get when a high-volume bulk sampling is done on a filter substrate.

RSPM is that fraction of TSPM which is readily inhaled by humans through their respiratory system and in general, considered as particulate matter with their diameter (aerodynamic) less than 2.5 micrometers. Larger particles would be filtered in the nasal duct.

PM10 is a subset of TSPM and stands for particulate matter with aerodynamic diameter less than 10 micrometer.

However, these are all some rules for convenience; in practice, most of the air-borne particles are non-spherical and it is difficult to assign a diameter. Further aerodynamic diameter is also a mathematical concept (an imaginary sphere having unit bulk-density and the same settling speed as that of the actual particle) and hence is related through the density (mass per unit volume) of the particle.

Thank you Krishna Moorthy Sir.

Your answer gives me a better sight in understanding of different words used in particulate matter research.

The RSPM definition is reported in some international standards, as well as thiose for the inhalable and thoracic fractions of PM (EN481, 1993 - Workplace atmospheres. Size fraction definitions for measurement of airborne particles; ACGIH, 2014 - Threshold limit values for chemical substances and physical agents and biological exposure indexes, Cincinnati, Ohio; ISO 7708,1995 - Air quality - Particle size fraction definitions for health-related sampling). These size fractions are widely used for risk assessment in occupational environments.

Standard methods for collecting PM10 and PM2.5 are reported somwhere else (EN 12341, US 40 CFR Part 53). These PM fractions are mostly used for air quality assessment.

Thank you andrea

TSPM=SPM+RSPM,

RSPM inclutes PM10, PM2.5 and other fine particles.

SPM is having aerodynamic diameter of 100 Micrometer or less.

Thank you. Very useful information.