Free Custom Simulations Available

The creator of this website, Dr. Neil Klepeis, is available to perform custom simulations of tobacco smoke exposure for policy or education purposes -- in most cases free of charge. This service is intended to assist those website visitors who may want to explore a specific exposure situation or who may want to compare a variety of different potential exposures, such as those taking place in sophisticated multizone environments or involving prescribed human activity patterns.



Revised NAAQS for Fine Particles

The USEPA has announced the revision of their 24-h National Ambient Air Quality Standards (NAAQS). The 24-h standard for fine particulate matter was reduced from 65 to 35 micrograms per cubic meter (μg/m³).

This is an important development, because it indicates that the USEPA has reviewed many peer-reviewed studies, and they have found that harm can occur from exposures to fine particles that exceed the new, lower level.


New Research on Residential Secondhand Smoke Exposure

Two new research papers on the simulation of exposure to secondhand smoke occurring in residences are being published in the journal Atmospheric Environment, authored by Dr. Neil Klepeis and Prof. William Nazaroff. (links: 1 , 2).

These papers contain detailed simulation results of likely exposures that can occur in homes for a variety of ventilation conditions and occupant behavior patterns.



Bar and restaurant simulations

Neil -
I echo Martin's comments: thank you for putting this info on-line, and for your earlier work on outdoor smoking. With legislative moves towards non-smoking in bars and similar premises in Australia, there is now a lively debate (which, with the exception of Queensland, health interests are not generally winning) about how enclosed or unenclosed a place should be before before smoking is permitted/prohibited.

We actually have laws which say that as long as a place is more than 25% open (perimeter walls + ceiling, or sometimes just a % of wall area), it's OK to smoke.

Policy officers have been unable to find relevant information which associates degree of enclosedness with level of passive smoking exposure/risk for customers and staff.


Added Particle Deposition

I've added particle deposition to the simulations. The inclusion of particle loss due to deposition onto surfaces doesn't change the results very much, but it is a well known phenomena that acts to reduce airborne levels of SHS particles. Ventilation is usually a much stronger factor than deposition in removing SHS particles from a given location.


Bar and Restaurant Model

This simulation is of smokers in an enclosed (indoor) bar or restaurant over a 2-hour period where there are designated smoking and nonsmoking rooms. The two rooms are well-mixed and connected by a doorway or open passage.

You may select the dimensions of each room (Length x Width x Height in feet), the overall rate of outdoor air exchange (h-1), which is apportioned to each room according to their volumes, the air flow rate between zones (m3 h-1), which is currently the same in each direction, and the total number of cigarettes smoked in the smoking room of the venue over the 2-hour period.

Multiple smokers can be active simultaneously. Each cigarette lasts 10 minutes. Cigarette starting times are assigned randomly. A given cigarette has an equal chance of being lit during any minute of the 2-hour period.


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