When water reached the front steps of her house, driven by the storm, Yenny Ramirez was worried about more than Harveys floods. A strange smell drifted through her neighbourhood.

The odour was extremely strong, thick, she said. During the storm we were inside. We couldnt really go outside. At one point we turned off the A/C just so the smell wouldnt be so bad.

The Houston suburb of Manchester did not suffer the extensive flooding brought by Harvey around the region. But rainfall did cause a tank failure at a refinery, leading to a leak of chemicals including an estimated 1,881lbs of benzene, a carcinogen just a fraction of nearly 5.3m lbs of unauthorised pollutants that were attributed to the storm, according to an Environmental Defense Fund analysis.

The leaks underlined that Harveys damage was not only at ground level, but advocates and residents fear that the citys full attention will be on reconstruction and flood prevention and that air quality wont be a priority. While Augusts rains inundated rich and poor alike, air pollution in Houston disproportionately affects low-income, mainly Latino communities next to industrial facilities, such as Manchester.

Sandra Martinez and her husband paid $700 a month for the three-bed house in Manchester where they lived with their six children. The rent, it was so reasonable, she said. But air pollution after Harvey drove them out.

You could literally smell it in the house too and I was like, Lord Jesus, I just pray for my kids. Because you dont know if there was a chemical spill, said Martinez, a clerk at a dry cleaning firm. She said the family was constantly checking the stove and the boiler, searching for sources of the foul air. They realized that outside pollution had swept into the kitchen, living room and bedrooms.

After family members suffered health problems, such as bronchitis, asthma, nausea, nasal congestion, nosebleeds, headaches and stomach aches, they decided the miasma during the storm was the last straw.

The family moved out on 4 September, 10 days after Harvey made landfall. Were very blessed and fortunate, Martinez said. It cost us an arm and a leg to try to get the money together but we got out.

Manchesters residential streets are encircled by the Valero refinery, the Buffalo Bayou ship channel, two freeways, freight rail tracks and other industrial facilities. Refineries and petrochemical plants stretch east along the channel for 20 miles.

The wealthiest, majority-white neighbourhoods are on the other side of downtown, where the bayou is flanked by multimillion dollar mansions, parkland and golf courses.

We know the priorities are Americans white people, rich people, said Celia Munoz. She has an eight-year-old son and a six-year-old daughter with asthma and eczema. They attend an elementary school near a chemical plant and a junkyard, and Munoz worries about the lack of a full-time nurse, and that missing class because of illness will affect her daughters education.

Harvey acted like a mask for all of these issues. Easier to focus on a natural disaster thats short term than all these [long-term] problems, she said. The storm is keeping peoples minds off this.

Munoz lives just outside Manchester. I want to move farther away. My husband wants his children to have the same childhood he did, she said through a translator. To him this is home.

Research published in 2016, by the Union of Concerned Scientists and Texas Environmental Justice Advocacy Services (Tejas), found that the concentration of a carcinogen, 1,3-butadiene, was 174 times higher in the Harrisburg-Manchester area than in the prosperous west Houston neighbourhood of West Oaks-Eldridge, where the cancer risk is 30% lower.

Since 1998, almost every two years there have been studies about the air toxins in this particular area, and they all basically draw the same conclusion, said Juan Parras, executive director of Tejas. The question is what are you going to do about it?

The state, he continued, says were open for business. You dont like it, move out.

The choice is rarely that simple. Ramirez, a 35-year-old originally from Mexico, has lived in Manchester for 13 years with her husband, a carpenter named Carlos. They have three children, aged 13, 10 and two. She enjoys being near friendly neighbours, even though her house stands a quarter-mile from a 10-lane freeway, a two-minute walk from 26 railroad tracks, and less than half a mile from the refinery.

It would feel weird just picking up and leaving everything after so many years. Weve put so much into our home, she said. But waves of foul stench frequently waft into the home, and can get so acrid they irritate the throat, especially when it rains. I told my husband I dont like being here with the smell when Im pregnant, Ramirez said. My husband said, its affordable.

Jennifer Horney, a public health professor at Texas A&M University, has been monitoring air quality in 25 households in Manchester since December 2016. That dust has a lot of polycyclic aromatic hydrocarbons in it, she said. Just because theyre not gutting their houses and dealing with mould [from flooding], doesnt mean that theyre not dealing with a number of challenges to their environment indoors and outdoors.

The Environmental Protection Agency (EPA) issued a statement saying that the benzene leak does not indicate levels of concern for the community. Still, Horney said, If we dont find levels that are actionable by regulatory agencies that doesnt mean that those levels arent harmful to peoples health.

Activists argue that Harvey underscored the need for more reliable air quality data during natural disasters some monitors were turned off because of the storm, while the state suspended some environmental rules. Valero initially estimated a leak of only 6.7 pounds of benzene.Long concerned that Texas is too lenient on polluters, campaigners also fear that the EPA is being defanged by the Trump administration.

In October the EPA named Michael Honeycutt, chief toxicologist at Texas environmental regulator, as chairman of its Science Advisory Board. Honeycutt has been dismissive of attempts to lower ozone levels. In November the White House nominated Kathleen Hartnett White, a former head of the state agency, to chair its Council on Environmental Quality, though she is sceptical of the scientific consensus on climate change and in 2015 wrote an article lauding carbon dioxide and the environmental benefits of fossil fuels.

She was re-nominated in January despite Democratic attempts to thwart her appointment on the basis she is unqualified.

Activist Patricia Gonzales said she felt like nothing under the current administration. Were just sitting ducks, basically, in these areas where the refineries are, all over the States, she said. Gonzales lived in Manchester for three years in the 1990s but left after she and her baby fell sick.

We dont have the kind of money that most Anglo people have when they go to higher education, colleges and stuff like that, she said. They go live in the areas where there arent refineries. We have to live in areas where we can afford lower-priced homes and so were at a disadvantage.