Impact of wildfires on the air quality of Mexico City, 1992-1999.

Wildfires in Mexico increased in 1998, compared to information for the last 6 years. The average number of wildfires in the Mexico City Metropolitan Area (MCMA) for this year (1998) were 58% (1916 events) more events than the 1992-1997 (average cases 1217 events). Mexico City affected area corresponds to 1.3% of the national affected area. The purpose of this paper is to evaluate the impact on the particles air quality due to the wildfire emissions at the MCMA and surrounding areas. Using the corresponding US EPA emission factors for wildfires, the tons of particulate matter, nitrogen oxides, carbon monoxide, and total hydrocarbons emitted by this source for the MCMA case were obtained. The calculated emissions during wildfires were correlated with the levels of particles present in the atmosphere. A comparison of the concentration levels of particles, both as PM10 as well as TSP, were made for the years 1992-1998, during wet and dry season, being March, April, and May the critical months due to the presence of wildfires. A good correlation is observed between particulate wildfire emissions and particulate air quality, being stronger for TSP. A clear impact on the particles air quality due to the increase of wildfires in 1998, is observed when this year is compared with 1997, presenting an increment of 200-300% for some monitoring stations.

Training farmworkers about pesticide safety: issues of control.

Farmworkers experience a lack of control over the conditions of their work environment. In trying to reduce the effects of exposure to pesticides, most health care providers give instructions to farmworkers about how to protect themselves. Outreach programs that target farmworkers focus on health education and recommend washing hands, wearing appropriate clothing, and avoiding direct contact. The research reported in this paper shows that farmworkers in North Carolina perceive many of these preventive measures to be outside their control. The ability of farmworkers to engage in safe practices depends on their capability to communicate with their employer, have positive work relationships, and the availability of protective equipment. The perceptions of control identified in this paper are issues that service providers and policy makers should consider to provide programs that will effectively promote pesticide safety and healthier farmworkers.