The Boston Marathon bombings prompted a new era of stepped-up security at public events in Greater Boston, and that will be visible at this year?s Topsfield Fair, which runs from Oct. 4 to 14.?Even though you may see additional security around, people should not feel it?s an unsafe situation at all,” Topsfield Fair General Manager James O?Brien explained at his annual pre-Fair media briefing on Thursday evening. “We are going to have tables set up at every gate and we will be looking in all bags.”O?Brien said the fair management has been working with Topsfield Police, State Police and U.S. Air Force personnel – a trained security force of 180. He said inspections of bags and coolers will not be intrusive, and both will be allowed on the grounds. Bomb-sniffing dogs will sweep the grounds during a lockdown early on the fair?s opening day, and there will be mirror undercarriage inspections of all vehicles entering the grounds (excluding parking lots).Because the Topsfield Fair is among the top five venues in the state in terms of crowd size, O?Brien said last year state police evaluated its security and gave the fair high marks.?Because of what happened in Boston this spring, it warrants another level of security and that?s why we?ve stepped up to do that,” O?Brien said, emphasizing there is no threat of any sort and that 180 security personnel have been trained this year. “We?re different than a lot of venues. We have a fenced in location and security gates (for vehicles) ? People are as safe at the Fair as they are in their own home.”Also in keeping with the Boston Strong theme, this year?s Fair promotional pieces – brochures and posters – are blue and yellow. And the theme of the Fair this year is, “Make Time for Great Time at The Topsfield Fair.”O?Brien noted that the Fair, which in its early years was a traveling event held in communities around Essex County, including Lynn, in different years, has grown to among the largest agricultural fairs.?It is the Topsfield Fair, but just like the state said, it?s one of the top five events in the state,” O?Brien explained. “Our surveys show we draw people from Southern New Hampshire, from Lowell and Lawrence, from Worcester and from south of Boston.”O?Brien said he hopes attendance hits 500,000 this year. Last year, with eight days of heavy rain, attendance was down to roughly 380,000.?We try to control what we can but we can?t control the weather,” O?Brien said. “But even in poor weather Topsfield is a great place to be. We have a lot of hot top so you?re not walking in mud, a lot of buildings and our activities go on rain or shine.”The fair?s primary mission remains agricultural education and toward that end, the Fair welcomes thousands of elementary students for free each weekday, provides free lunch to the first 500 and guides them through the Fairgrounds on various planned lessons. The Fair also awards more than $27,000 in scholarships each year, and to aid that cause, the Fair?s annual 5K Run/Walk/Stroll will be held Sept. 29.