Joseph C. Zadroga, whose lobbying helped deliver health benefits to thousands of emergency workers whose health was impaired by inhaling dust and debris at ground zero after the 2001 terrorist attack on the World Trade Center — although his efforts came too late for his own son, a New York City detective — died on Saturday after being hit by a car in Pomona, N.J. He was 76.

His death was confirmed by his son Joseph F. Zadroga.

Early Saturday afternoon, the elder Mr. Zadroga was visiting his wife at the Bacharach Institute for Rehabilitation. According to the Galloway Township police, he was standing outside his parked car when he was struck by an SUV that apparently accelerated accidentally and pinned him under it. He was pronounced dead at AtlantiCare Regional Medical Center.

A retired North Arlington, N.J., police chief, Mr. Zadroga was instrumental in the passage by Congress in 2010 of the James Zadroga 9/11 Health and Compensation Act, which provides federal medical benefits, including monitoring and treatment, to police officers, firefighters and emergency medical workers who became ill as a result of their exposure to the contaminants in the aftermath of the 2001 devastation in Lower Manhattan. Mr. Zadroga and others successfully pushed Congress to reauthorize the legislation in 2015.

The death of his son James was the first death of a public employee that was officially linked by an autopsy to time spent by an emergency worker at ground zero.

James Zadroga died in 2006, at 34, after spending some 500 hours engaged in recovery efforts at what became known as the Pile. By the following May, after sifting the rubble for human remains, workers had removed 1.8 million tons of tangled wreckage. He eventually qualified for disability pension benefits and received a one-time payment to cover lost income from the government compensation fund that expired in 2003.

His death came a year after his wife, Rhonda, died of a heart attack, which left him to raise their 4-year-old daughter, Tyler Ann. She was orphaned when he died bringing her a baby bottle, and she was brought up by his parents, his brother and his sister-in-law.

“I just want everybody out there, the victims who got sick, to have the health care that they deserve, because Jimmy didn’t get it,” Joseph Zadroga said at a rally in 2014.

Patrick Hendry, the president of the Police Benevolent Association, New York City’s largest police officers’ union, said in a statement: “Joseph Zadroga took on a fight that no father should have to face. But he fought for his hero son with incredible courage and helped every single 9/11 responder in the process.”

After his son died, Mr. Zadroga was invited by Representative Carolyn Maloney, a Manhattan Democrat, to testify before Congress, and he helped mount a nationwide campaign for the health care legislation that was supported by the comedian and talk show host Jon Stewart and other celebrities.

In his testimony, Ms. Zadroga quoted from a letter written by his son: “Everyone praises the dead as heroes, as they should, but there are more living suffering than dead.”

The Ocean County coroner had originally found that James Zadroga died of “respiratory failure” resulting from a “history of exposure to toxic fumes and dusts.”

But about a year and a half later, New York City’s chief medical examiner, Charles S. Hirsch, concluded that the particles in his lungs were from the abuse of prescription drugs. (His family said that if he had taken painkillers, it was because he found it increasingly painful to breathe.) A third opinion, by Dr. Michael Baden, who had been the city’s chief medical examiner in the late 1970s, supported the coroner’s original finding.

The conflicting opinions entangled Mayor Michael R. Bloomberg, who endorsed Dr. Hirsch’s conclusion and said: “We wanted to have a hero, and there are plenty of heroes. It’s just in this case, science says this was not a hero.” The mayor later apologized, saying, “I believe that James Zadroga was a hero for the way he lived, regardless of the way that he died.”

James Zadroga is not listed on the 9/11 memorial.

Joseph Charles Zadroga was born on April 2, 1947, in Newark. His father, Charles, worked for RCA. His mother, Ann (Czyc) Zadroga, ran the household.

After graduating from North Arlington High School, Joseph earned a bachelor’s degree in criminal justice from William Paterson College (now William Paterson University) in Wayne, N.J., and a master’s in emergency management from Fairleigh Dickinson University. He served in the Army in Vietnam from 1966 to 1968.

In addition to his wife, Linda (Baczewski) Zadroga, and his son, Mr. Zadroga is survived by his sister, Paula Bates, and two grandchildren.

Joseph Zadroga worked for the North Arlington Police Department from 1970 until 1997, when he retired as chief. He later taught at the Bergen County Police Academy. Tattooed on his forearm were a crucifix, his son’s name and the words “Not Forgotten.”

“Joe turned his son’s tragedy into something that really helped so many people,” Michael Barasch, who was James Zadroga’s lawyer, told northjersey.com, adding that James “didn’t die in vain, because of the autopsy his parents ordered.”

“Without that,” he said, “we would have never had the evidence to get Congress to act.”