Measurement of some Air Pollutantsin Printing Units and Copy Centers Within Baghdad City

Emissions of particulate matter from nanopapers as well as inks and organic solvents during the printing operationand copying machines constitute a threat to human health, especially with long time exposure in closed working environments. The present study was conducted in some printing houses and copying centers of Baghdad city during February and April.The studyproved the occurrence of an air pollution problem concerning lead and zinc contents in all the study sites. The levels of Pb, Zn and Cu were collected by low volume sampler from the air of the study sites then filter papers digested and determined the heavy metals by flame atomic spectrophotometer. Particulate matter was measured by Aerocet, Microtector meter device was used to measure nitrogen dioxide, sulphur dioxide, carbon monoxide and volatile organic compounds . The highest concentrations of lead and zinc were recorded in the printing houses air (2.75μg/m) and (51.95μg/m) respectively. In contrast,copper concentration in the copying offices air recorded a significantly higher value (0.65μg/m) (P>0.05) as compared to that in printing houses. Fine particulate matter(PM2.5)(particles diameter < 2.5 μm) hasrecorded the highest concentration (44.50μg/m ) in printing houses, followed by the highest concentrations of inhalable coarse particulate matter (PM10) (particles with diameter of 2.5 to 10 μm) and total suspended particulates (TSP)(the total of solid particles) (477.66 and 667.00μg/m) respectively in printing houses. The results obviously showed the highest concentrations of carbon monoxide (CO) (6.13 ppm) and volatile organic compounds (VOCs) (21.88 ppm) in printing houses, while nitrogen dioxide (NO2) recorded its highest concentration (1.44 ppm) in copy centers. Lead, zinc, copper, PM2.5, PM10 and TSP concentrations exceeded the permissble levels in all study sites converselywith the levels of carbon monoxide , nitrogen dioxide, sulphur dioxide(SO2) and volatile organic compounds that were within permissible air quality standards.


Introduction:
The increasing demand for printers and copying devices without knowing their health risks of volatilization of inks and solvents caused a lot of health and respiratory risks to workers and ordinary people as well as a potential source of indoor air pollution. Several studies have indicated prevalence of many of respiratory symptoms pulmonary restrictive sings and oxidative stress in photocopying and printing workers (1,2). Printers and copying devices during their operation emit various types of pollutants into the indoor air environment including nanoparticulate matter released into the air, together with other semi-volatile organic nanoparticles, and newly formed gaseous co-pollutants such as volatile organic compounds and other toxic gases nitrogen dioxide, sulphur dioxide, carbon monoxide), lead, nickel, benzene, arsenic, ammonia, paper minutes and inks particle (3)(4)(5). The basic composition of the particulate matter consists of iron, lead, zinc, carbon and many other metals produced by heat-generated during printing process from inks and toners as well as paper particles (6,7). Synthetic resins, pigments, and additives make up the elements of toners, toner layer contains solid surface or granular surface, toners structures differences according to the printing device such as Konica Minolta, Canon, OKI, Hewlett-Packard, Lexmark, Epson, Dell, Ricoh, Brother, and Xerox (8). The volumes of the inks particles have gradually decreased to improve print quality. Because of the small size of these molecules, they can penetrate into the respiratory system and stabilize withinlungs deeply during operation and maintenance. Epidemiological studies reported the prevalence of chronic cough, wheezing, nasal blockage, excessive sputum production, breathing difficulties, and shortness of breath, in copier operators (9). Printing inks and toner containing the heavy metals form part of its components. US environmental protection agency listed many of heavy metals that content in offset printing inks such as barium, cadmium, copper, lead, mercury, nickel, zinc, arsenic, chromium, selenium and silver (10). Most heavy metals are dangerous because they tend to bioaccumulatein body human (11).
Particulate matter is a key indicator of air pollution brought into the air by a variety of natural and human activities. The size of particles has been directly linked to their potential for causing health problems. Many health effects like eye irritation, dry throat, runny nose, sneezing, cough, tiredness, irritability, difficulty concentrating, headache, dizziness, and skin irritation associated with these particulates reported (12).Particulates with diameter 10 μm emitted from printing inks pose health risks and can lead to lung inflammation and lung cancer due to the contamination of these molecules, which can have a toxic effect within cells and be mutagenic (13).The exposure to particulate matter and volatile organic compounds emitted from copying devices may cause lung problems, inflammation, DNA damage and genotoxicity (14).High levels of nanoparticles (PM0.1) emitted from photocopying toners contain organic and elemental carbon, metals including iron, zinc, titanium, chromium, nickel and manganese (15).Ultra fine particles are released during printing activities or arise from ozone reaction with volatile organic compounds emitted from printers .Ultra fine particles are influenced by indoor ventilation conditions as well as printer parameters such as printer type, age of printers and number of pages printed. Printers release a large amount of volatile organic compounds VOCs during printing activities, the concentration levels of VOCs styrene, benzene, chlorobenzene, toluene, ethylbenzenes, styrene and xylenes increased during printing activities especially during peak hours of printing and the source of styrene was toner dust in printer cartridges (16,17).
Industrial processes are the largest contributor to the emissions of human volatile organic compounds and their global emissions are estimated at about 27 g/year resulting from the use of industrial solvents in dyes, inks, etc. Symptoms of direct exposure to VOCs nose and throat irritation, headache, skin allergies, nausea, dizziness and fatigue (18,19). The US Environmental Protection Agency has classified VOCs as hazardous air pollutants, for example, benzene. Many studies have revealed that exposure to benzene or products containing benzene cause different types of leukemia (20). Here, current study sought to assess air quality of the printing houses and copy centers environment and detectthe of presence some concentrations of heavy metals (Lead, zinc, and copper) and particulates matter emitted from working environment.

Sampling Sites
Work sites included (two printing houses and seven copy centers) on both sides of Karkh and Rusafa within Baghdad city/Iraq. Al-Nahrain press for printing and publishing Southwest of Baghdad (33°18'36"N, 44°21'39"E). The University Press and Publishing House located inside the University of Baghdad, Jadriya (33°16'25"N,44°22'56"E), and seven copy centers of Bab AlMu'adham(33°21'07"N,44°23'34"E) . In order to compare the quantity of pollutants in presses and copy centers offices, the samples were collected through daily working hours estimated from 6 to 9 hours per day .

The Study of work environment pollutants
Three metals: Lead (Pb), Zinc (Zn) and Copper (Cu), in addition to particulate matter (PM 2.5 , PM 10 ) Total Suspended Particulates (TSP) and some air pollutants (CO, NO 2 , SO 2 , VOCS) were collected and covered the study sites.

Collecting some of heavy metals samples
A device known as (sniffer) Low volume air sampler was used to estimate the level of Lead, Zinc, Copper in the air presses and copy centers after the collection. The samples were digested according to standard methods (21) and heavy metals Pb, Zn, and Cu were determined by Flame Atomic Spectrophotometer according to Standard methods (22). The total suspended particulates and particulate matter of the sizes (PM 2.5, PM 10 , TSP)in the airwere measured during February and April by Aerocet 531 device close to the breathing level of the workers in their work place in (milligrams) per cubic meter.

Air polluted gases and VOCs
Air polluted gases (NO 2 , SO 2 ,CO) and VOCs were measured in the working environment close to the breathing level of workers by Microtector meter device II G460 of the unit (ppm) to see how it affects the respiratory health of the workers.

Statistical Analysis
The Statistical Analysis System ANOVA (23) was used to show the effect of a different group in study parameters. The least significant difference-LSD test was used to significantly compare between the means in this study.

Results and Discussion
Heavy Metals in the working environmentair In order to improve indoor air quality, it is necessary to study the sources of emissions from chemical compounds. Descriptive statistics of heavy metal concentrations in the air of study sites are summarized in (Table 1).The highest value of lead (2.75±0.06μg/m 3 ) was observed in the air of Printing housesenvironment compared to the least mean value of lead (2.44±0.09μg/m 3 ) in copying centers environment (Table.1).There were no significant differences between the study sites. The results of the current study exceeded the globalthe permissible limits (24).This means that there is lead contamination increasing with the increase in working time with using printing inks. A previous study indicated the high percentage of lead in air pressesin the printing housesair near the furnace (7) . Inks used in printing and copying contain additives and solvents that are the main reason for the increased concentration of lead in the air of the working environment. Heavy metals lead, Cadmium, hexavalent chromium, and mercury were found in printing inks which are toxic heavy metals that are hazardous to human health (25). Zinc recorded the highest value (51.95±6.52 μg/m 3 ) in the air of the printing houses environment compared to the least value in the air of copying centers (42.21±3.69μg/m 3 ) (Table1). Zinc concentrations in the study sites exceeded the global determinants at high rates. The high value of this component is due to its emission from the parts of the machines due to friction with each other such as the bonding tools as well as the components of inks of heavy metals because inks contain heavy metals such as lead, cadmium, zinc, copper, barium, selenium, chromium, arsenic, nickel, which are used as inks in offset machines with pigments blue, red, yellow, green, and the basic black (10). The highest value observed in the mean of the copper was in the air of copying centersenvironment (0.65±0.05 μg/m 3 ) with significant increasing at (P<0.05) compared to the mean of copper in the air of printing houses environment(0.24±0.02μg/m 3 ).Copper concentrations exceeded the permissible global limits. This increase is due to the friction of the parts of the machines usually manufactured from Copper as well as heating the printing inks during the printing process which contributes to their emission to the working environment (Table.1). Figure 1 shows the percentage of heavy metals pollution in papers binding section was the least compared to printing and copying sections, The machines were far from it, which made it record lower percentages of heavy metals, and this indicates that it is the closer the work to the printing and copying devicesthe more air pollution by heavy metals .

Particulate Matter in the air of working environment
The results in the (Table2) show data mean of particulate matter and total suspended particulate in all study sites. It seems clear that the highest values of PM 2.5 and PM 10   The statistical test referred to a highly significant differences in the mean of PM 10 values between the air of printing houses and the air of copying centers environment pollutants according to the value of LSD (106.48,P<0.01) Moreover, it was noticed that highly significant differences were noticed in the mean of TSP concentrations between the air of printing and the air of copying centers environment pollutants according to the value of LSD (156.37, P<0.01) ( Table.2). These differences are due to the poor ventilation and the lack of air fans in the printing environment especially that printing presses have a large unhealthy construction areas compared to the copying centers which are usually small as well as printing houses contain many machines ranging from offset machines used for printing, cutting machines, thermal machines and many machines of different sizes vary according to the nature of its work. Particulates are also emitted from shearing machines in the presses to the working environment and because of the workers proximity tothese machines and small particulates size, they enter through the respiratory tract of workers and cause health problems for them (27).Fine particulate matter shows less density after one hour of the printing operations and the resting time (28) .
As forcomparing the concentration values of particulate matters in printing houses and copying centers during February and April, the readingsrecorded a noticeable increase in the percentage of concentrations during April compared to February in all of study sites, printing houses particulate matters recorded obvious differences (Fig.2) (Fig.3).
The difference in the concentrations of particulate matter is due to the increase in air temperature and the increased demand for publications during April compared to February, as well as heating the printing inks in machines for the purpose of fixing the pigment particles on paper that contributed to raising the temperature of the work sites.

Contaminated Gases and VOCs in the air of working environment
There are many global studies indicating the existence of printing and copying centers machinery emissions which is a complex mixture of molecules,and volatile organic compounds.The current study indicates the highest value of CO concentration reached (6.13 ppm) in the air of the printing environment (Table3) with significant differences (P<0.05) compared to copying centers which indicated that no air pollution with CO. Nitrogen dioxide and sulfur dioxide is considered as a major air pollutant emitted from various industrial sources (29) .The highest value of NO 2 reached (1.23 ppm) in the air of printing environment compared to the least value (1.44 ppm) recordedin copying centers environment which means there wereno significant differences among thestudy sites.On the other hand,SO 2 did notrecord any concentration in both environments of printing and Copying centers.This means that there is no pollution in these sites with SO 2 .The results of gases concentrations did not exceed the permissible limits. VOCs recorded thehighest value (21.88 ppm) in the air of printing environment compared to the environment of copying centers (2.14 ppm) (Table.3). This study recorded significant differences (4.731) (p<0.05) between the study sites.This may be due to composition of toners and inks used in office equipmentfor example, printing houses inks are liquid, while the copying centers offices use powder dry ink, the toner cartridge as well as the size of work place, size of papers, size of printers,and number and type ofmachines. Emissions from printers and copiers also depend on the operation modes and thematerialsused (30). VOCs measurements did not exceed global permissible limits. Office machines release volatile organic compounds from heating up the drum and toner up to 160 °C for compress toner on paper during peak hours of printing process. Printing inks are diluted by organic solvents emitted to the atmosphere during the printing process and are generated by heating and volatiles from digital printing ink, digital printing inks and flexographic which represent potential sources for volatile organic compounds. It is necessary to study emissions of chemical compounds used in the construction of office materials, furniture and office equipment, especially in low-ventilated closed environments (31)(32).

Conclusions:
The current study isconducted to assess the air quality of the working environment in printing houses and copying offices to improve the safety of workers . Although the working environment varies between the printing houses and the copying offices in terms of the quality of the printers used, the principle of their work, their size and the printing method used, age of printers, types of ventilation, number of copies makeon an average work day as well as the size of the printing houses places compared to the size of copying offices.However,the results indicate thatconcentrations of heavy metals (Pb, Zn, and Cu) in the air of all the study sites exceed the permissible global limits. Concentrations of particulate matters (PM 2.5 , PM 10, and TSP) also exceed the permissible global values in printing presses and copy centers which means contamination of heavy metals and particulate matter in the air of the working environment in printing houses and copy centers.The concentration of gases, by contrast,isvery little and doesnot exceed the permissible limits at all of study sites.
In accordance with these conclusions, the study recommends the following:  It is necessary to use inks that don't contain hydrocarbons or low aromatics and that old machinesshould be replacedwith modern digital machines.  Containers of inks should be cleaned in open areas and wiped with a cloth dampened with water. Inks should not be released to soil or water to prevent pollution of groundwater and soil .
 Ventilation in the workplace should be improved and adequate ventilation to air should be provided to get rid of odors from the inks and chemical vaporization  Workers in printing houses and copying offices, especially thoseexposed for long periods of time, should be educated on how to deal with the equipment, toners in addition toprovidingthe necessary personal protective equipment.