Sampling and composition of airborne particulate matter (PM10) from two locations of Mexico City

The PM10 airborne particulate matter with an aerodynamic diameter ≤10 µm is considered as a risk factor of various adverse health outcomes, including lung cancer. Here we described the sampling and composition of PM10 collected from an industrial zone (IZ), and a commercial zone (CZ) of Mexico City. The PM10 was collected with a high-volume sampler in the above mentioned locations and both types of PM10 sampled were characterized by the content of polycyclic aromatic hydrocarbons (PAHs), metals, and endotoxin. The endotoxin PM10 content from IZ and CZ displayed 138.4 UE/mg and 170.4 UE/mg of PM10, respectively.

The data are within this paper. Value of the data Air quality can be evaluated partially by the content of particulate matter with an aerodynamic diameter r10 mm (PM 10 ).
Specific PM 10 components could be responsible for effects on human health. PM 10 sampled reveals the presence of harmful components such as polycyclic aromatic hydrocarbons (PAHs) and oxidant metals.

Data
Here we describe the sampling and composition of PM 10 collected from an industrial zone (IZ), and a commercial zone (CZ) of Mexico City.

PM 10 sampling
Particulate matter with an aerodynamic size of 10 μm (PM 10 ) was collected using a high-volume sampler [1] from an Industrial zone (IZ) located in the northern part of Mexico City, where several industries are located. This area, which includes some neighboring municipalities of Xalostoc in the State of Mexico, harbors a wide variety of industries related to steel, grinding minerals, plastic manufacturing, industrial soap production, concrete, and cleaning products. Fig. 2. The composition of particulate matter with aerodynamic diameter of 10 μm (PM 10 ). PM 10 is a complex mixture of polycyclic aromatic hydrocarbons (PAHs), metals and endotoxin, among others. PAHs were analyzed by high-pressure liquid chromatography (HPLC); metals by particle-induced X-ray emission (PIXE) analysis, and endotoxin content was analyzed by limulus amebocyte lysate (LAL) assay.
The other selected area for collecting particles is a commercial zone (CZ) located in the neighborhood called La Merced, which is a traditional food market area found closely to the Mexico City Historic downtown. Every day, several trucks with diesel and gasoline engines deliver food products in this area. Also, there is an important bus terminal station (Terminal de Autobuses de Pasajeros de Oriente) in this area. In addition, there is a heavy private and public transportation based on diesel or gasoline engines constituting an additional source of pollution in this area.
Sample collection of PM 10 was performed using one cellulose nitrate filter per day, excluding the rainy season (June-September). PM 10 from the whole period (October-May) was recovered from filters and a PM 10 -year pool was stored in free-endotoxin sterile vials at 4 1C until usage for experimentation and physicochemical characterization (see Fig. 1).

PM 10 composition
The characterization of collected particles was initially performed to identify the main components of PM 10 , which are related to polycyclic aromatic hydrocarbons (PAHs), metals and endotoxin. Then, using dichloromethane extraction followed by high-pressure liquid chromatography (HPLC; Agilent HP, 1100 series) PAHs content was determined [2]. Elemental metal analysis to the pool of PM 10 [3] was performed by particle-induced X-ray emission (PIXE) using a proton beam produced by a 9SDH-2 Pelletron accelerator. Endotoxin content was measured through a kinetic assay of Limulus Amebocyte lysate (LAL) assay according to the manufacturer's specifications (BioWhittaker, Walkersville, MD, USA) using Escherichia coli endotoxin as standard [4]. We have reported some of the most representative compounds of PM 10 , which includes PAHs, endotoxin and aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), chlorine (Cl), potassium (K), calcium (Ca), titanium (Ti), chrome (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn) and lead (Pb). Endotoxin results showed that PM 10 collected from both the industrial zone and the commercial zone displayed 138.4 UE/mg and 170.4 UE/mg of PM 10, respectively (Fig. 2).
Importance of PM 10 composition lies on the possibility to explain that biological effects associated to inhalatory exposure are different among polluted cities. Some of these effects are specially alarming because can be related to the acquisition of new characteristics such as invasiveness by targeted PM 10 cells, such as lung epithelial cells and PM 10 derived from one location can even be more harmful that other [5].